ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Books
  • Articles  (149)
  • Data
  • Development  (77)
  • Scanning electron microscopy  (74)
  • Springer  (149)
  • Oxford University Press
  • 2010-2014
  • 2005-2009
  • 1995-1999  (41)
  • 1980-1984  (48)
  • 1975-1979  (60)
  • 1935-1939
  • 1925-1929
  • 2012
  • 1999  (14)
  • 1998  (15)
  • 1997  (12)
  • 1984  (9)
  • 1981  (17)
  • 1980  (22)
  • 1979  (17)
  • 1978  (24)
  • 1977  (19)
  • 1925
  • Medicine  (149)
Collection
  • Books
  • Articles  (149)
  • Data
Source
Keywords
Publisher
  • Springer  (149)
  • Oxford University Press
Years
  • 2010-2014
  • 2005-2009
  • 1995-1999  (41)
  • 1980-1984  (48)
  • 1975-1979  (60)
    • +
Year
Topic
  • 1
    Electronic Resource
    Electronic Resource
    Ontogeny of the electric organ discharge and the electric organ in the weakly electric pulse fish Brachyhypopomus pinnicaudatus (Hypopomidae, Gymnotiformes) (1997)
    Springer
    Journal of comparative physiology 181 (1997), S. 111-119 
    Details
    ISSN: 1432-1351
    Keywords: Key words Weakly electric fish ; Gymnotiformes ; Development ; Electric organ ; Electric organ discharge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract I recorded the electric organ discharges (EODs) of 331 immature Brachyhypopomus pinnicaudatus 6–88 mm long. Larvae produced head-positive pulses 1.3 ms long at 7 mm (6 days) and added a second, small head-negative phase at 12 mm. Both phases shortened duration and increased amplitude during growth. Relative to the whole EOD, the negative phase increased duration until 22 mm and amplitude until 37 mm. Fish above 37 mm produced a “symmetric” EOD like that of adult females. I stained cleared fish with Sudan black, or fluorescently labeled serial sections with anti-desmin (electric organ) or anti-myosin (muscle). From day 6 onward, a single electric organ was found at the ventral margin of the hypaxial muscle. Electrocytes were initially cylindrical, overlapping, and stalk-less, but later shortened along the rostrocaudal axis, separated into rows, and formed caudal stalks. This differentiation started in the posterior electric organ in 12-mm fish and was complete in the anterior region of fish with “symmetric” EODs. The lack of a distinct “larval” electric organ in this pulse-type species weakens the hypothesis that all gymnotiforms develop both a temporary (larval) and a permanent (adult) electric organ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050098
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Ontogeny of rhythmic motor networks in the stomatogastric nervous system (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 361-365 
    Details
    ISSN: 1432-1351
    Keywords: Key words Central pattern generators ; Development ; Homarus gammarus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We used the lobster Homarus gammarus to study the ontogeny of neural networks involved in rhythmic behaviours. Since in the adult the neural networks belonging to the stomatogastric nervous system and controlling the rhythmic movements of the foregut are well characterised, we have studied them during ontogeny. While this foregut develops slowly throughout embryonic and larval stages, the neuronal population of these motor networks is quantitatively established since the mid-embryonic period. Moreover, in the embryo, this neural population is organised into a single functional network that displays a unique motor output. By contrast, in the adult the same neuronal elements are organised into three neural networks that express independent motor programs. Our results indicate that the multiple adult networks are partitioned progressively from a single embryonic network during development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050395
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    A nose that looks like a hand and acts like an eye: the unusual mechanosensory system of the star-nosed mole (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 367-372 
    Details
    ISSN: 1432-1351
    Keywords: Key words Cortical magnification ; Somatosensory cortex ; Development ; Evolution ; Behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The star-nosed mole (Condylura cristata) has a snout surrounded by 22 fleshy and mobile appendages. This unusual structure is not an olfactory organ, as might be assumed from its location, nor is it used to manipulate objects as might be guessed from its appearance. Rather, the star is devoted to the sense of touch, and for this purpose the appendages are covered with thousands of small mechanoreceptive Eimer's organs. Recent behavioral studies find that the star acts much like a tactile eye, having a small behavioral focus, or “fovea” at the center – used for detailed explorations of objects of interest. The peripheral and central nervous systems of the mole reflect these behavioral specializations, such that the small behavioral focus on the nose is more densely innervated in the periphery, and has a greatly enlarged representation in the somatosensory cortex. This somatosensory representation of the tactile fovea is not correlated with anatomical parameters (innervation density) as found in other species, but rather is highly correlated with patterns of behavior. The many surprising parallels between the somatosensory system of the mole, and the visual systems of other mammals, suggest a convergent and perhaps common organization for highly developed sensory systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050396
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The effect of genotype, age, sex, and caste on response thresholds to sucrose and foraging behavior of honey bees (Apis mellifera L.) (1999)
    Springer
    Journal of comparative physiology 185 (1999), S. 207-213 
    Details
    ISSN: 1432-1351
    Keywords: Key words Honey bee ; Behavior ; Development ; Neurobiology ; Foraging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Bees derived from artificially selected high- and low-pollen-hoarding strains were tested for their proboscis extension reflex response to water and varying sucrose concentrations. High-strain bees had a lower response threshold to sucrose than low-strain bees among pre-foragers, foragers, queens and drones. Pre-foraging low-strain workers showed ontogenetic changes in their response threshold to sucrose which was inversely related to age. High-strain foragers were more likely to return with loads of water compared to low-strain foragers. Whereas low-strain foragers were more likely to return with loads of nectar. Low-strain nectar foragers collected nectar with significantly higher sucrose concentrations than did the high-strain nectar foragers. Alternatively, low-strain foragers were more likely to return empty compared to high-strain foragers. These studies demonstrate how a genotypically varied sensory-physiological process, the perception of sucrose, are associated with a division of labor for foraging.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050379
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Excitatory interactions between antagonistic motor neurones underlying locust kicking and jumping during maturation after the adult moult (1997)
    Springer
    Journal of comparative physiology 181 (1997), S. 231-237 
    Details
    ISSN: 1432-1351
    Keywords: Key words Motor pattern ; Motor neurone ; Insect ; Grasshopper ; Development ; Schistocerca gregaria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract There is a change in the synaptic connections between motor neurones that underlie locust kicking and jumping during maturation following the adult moult. The fast extensor tibiae (FETi) motor neurone makes monosynaptic excitatory connections with flexor tibiae motor neurones that have previously been implicated in maintaining flexor activity during the co-contraction phase of jumping, in which energy generated by the muscles of a hind leg is stored. The amplitude of the FETi spike decreases when repetitively activated, and this decrement is larger in locusts immediately following the adult moult than in mature locusts. The decrement in␣the FETi spike is correlated with a greater decrease in the amplitude of the flexor excitatory postsynaptic potential (EPSP) in newly moulted locusts and in turn with the failure of these locusts to kick or jump. The results presented here indicate that the developmental change in the connections between the motor neurones contributes to the change in behaviour following the moult.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050109
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The photoreceptors and visual pigments of two species of Acipenseriformes, the shovelnose sturgeon (Scaphirhynchus platorynchus ) and the paddlefish (Polyodon spathula ) (1999)
    Springer
    Journal of comparative physiology 184 (1999), S. 37-47 
    Details
    ISSN: 1432-1351
    Keywords: Key words Fish ; Microspectrophotometry ; Retina ; Scanning electron microscopy ; Vision
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Scanning electron microscopy, microspectrophotometry, and spectrophotometry of digitonin extracts were employed to characterize the photoreceptors and visual pigments of two freshwater Acipenseriformes. The retinas of the shovelnose sturgeon, Scaphirhynchus platorynchus (Acipenseridae), and the paddlefish, Polyodon spathula (Polyodontidae) are dominated by large rods with long, broad outer segments. A second rod, rare and much narrower than the dominant rod, is present in Scaphirhynchus but not seen in Polyodon. The absorbance maximum of the visual pigment in the rods of Polyodon is near 540 nm; that of Scaphirhynchus near 534 nm. The retinas of both species contain substantial numbers of large, single cones, about 33% of the photoreceptors in Scaphirhynchus; 37% in Polyodon. Scaphirhynchus cone pigments have absorbance maxima near 610 nm, 521 nm and 470 nm, respectively. Polyodon cone pigments absorb maximally near 607 nm and 535 nm, respectively. All visual pigments are based on vitamin A2. The data are compared to those from other Acipenseriformes and are discussed in terms of lifestyle and behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Growth of embryonic chick tibiae in ovo and in vitro: A scanning electron microscope study (1979)
    Springer
    Calcified tissue international 27 (1979), S. 33-40 
    Details
    ISSN: 1432-0827
    Keywords: Chick embryo ; Bone ; Organ culture ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The study describes the ultrastructure of the mineralized portion of chick tibiae from 10 days in ovo to 2 days post-hatch. At 10 days a single mineralized cylinder surrounds the diaphysis. On its outer surface columnar trabeculae join to form ridges parallel to the long axis of the bone. These ridges are covered by another cylinder and form the haversian canals. At 11 days vascular invasion of the marrow cavity occurs and resorption of the endosteal surface begins. This type of periosteal deposition and endosteal resorption is repeated during and subsequent to embryonic development. The mineralized portion of 10-day chick tibiae cultured for 2 days in modified BGJ medium was compared with 10-, 11-, and 12-day tibiae in ovo. Cultured tibiae were similar in length and calcium content to 11-day tibiae in ovo. The form of mineral deposited in ovo and in culture was the same, namely, aggregates of spherical mineral clusters. Differences in culture included the following: (a) few concentric cylinders were deposited as compared with tibiae in ovo; (b) trabeculae were not arranged in rows and ridges in culture; (c) osteocytic lacunae were restricted to bases of trabeculae rather than uniformly distributed as in ovo; and (d) the endosteal surface of tibiae in culture appeared etched.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02441158
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Scanning electron microscopy and X-ray diffraction studies of human bone oxalosis (1980)
    Springer
    Calcified tissue international 30 (1980), S. 109-119 
    Details
    ISSN: 1432-0827
    Keywords: Oxalosis ; Human bone ; Scanning electron microscopy ; X-ray diffraction ; Oxalate titration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Postmortem scanning electron microscopy of human phalanges in a chronic uremic hemodialysis patient with hyperparathyroidism showed the presence of confluent abnormal rounded formations with a radial rosette-like crystalline pattern in the diaphysis as well as in the epiphyseal part of the bones. These fan-shaped configurations were found either as individual formations within bone trabeculae or as numerous aggregated crystalline deposits replacing large parts of the bone structure. The microdissected content of such large areas submitted to X-ray diffraction analysis revealed the predominant presence of calcium oxalate monohydrate or whewellite with some traces of hydroxyapatite. Oxalate titration analysis indicated the presence of 25% of oxalate, corresponding to 45% in weight of whewellite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02408615
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Correlation of freeze-fracture and scanning electron microscopy of epiphyseal chondrocytes (1978)
    Springer
    Calcified tissue international 26 (1978), S. 237-241 
    Details
    ISSN: 1432-0827
    Keywords: Epiphyseal chondrocytes ; Freezefracture ; Scanning electron microscopy ; Cell processes ; Membrane particles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Chondrocytes in epiphyseal cartilage were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using freeze-fracture techniques. Freeze-fracture replicas showed large numbers of fingerlike, 0.11–0.15 μm diameter, projections from the chondrocyte surface, with numerous 95–180 Å diameter intramembranous particles associated with both the cell membrane surface and these projections. With SEM, these cytoplasmic projections were also obvious, but appeared collapsed into clusters of globular-shaped projections on the surface of the chondrocytes. With freeze-fracture techniques, in which shrinkage artifacts were essentially eliminated, the cytoplasmic projections were often seen in intimate contact with the extracapsular matrix. However, with chondrocytes prepared by both SEM and conventional TEM, there was evidence of shrinkage, the cytoplasmic projections having little contact with the extracapsular matrix. These findings show that the cytoplasmic processes are not artifacts of tissue processing and provide morphological evidence in support of the hypothesis that matrix vesicles are of cellular origin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013264
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Scanning electron microscopical study on the fluorosis of enamel in rats (1978)
    Springer
    Calcified tissue international 25 (1978), S. 75-83 
    Details
    ISSN: 1432-0827
    Keywords: Rat ; Fluorosis ; Enamel ; Scanning electron microscopy ; Low temperature incineration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Sixteen 58-day-old male rats of Wistar strain, with a mean body weight of 179 g, were divided into two equal groups. Each group of eight animals was maintained for 70 days on drinking water, ad lib., containing no fluorine (control group) and 100 ppm of fluorine (experimental group). All specimens examined were obtained from the incisal portions of the incisors. The following types of enamel specimens were prepared for scanning electron microscopy: (1) acid-etched specimens; (2) acid-etched specimens followed by low temperature microincineration; and (3) fractured specimens. The enamel formed during high fluoride exposure showed marked hypocalcification, that is, the crystallite density in the prism core and interprismatic region was lower than that of control animals. The organic substances appeared to increase in these regions. These changes were prominent in the outer and middle enamel layers. Such changes following fluoride administration appear to indicate an inhibition of enamel maturation, that is, an inhibition of the mineral deposition and/or an inhibition of organic matrix withdrawal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02010754
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Structure and developmental expression of Ikaros in the Mexican axolotl (1999)
    Springer
    Immunogenetics 50 (1999), S. 336-343 
    Details
    ISSN: 1432-1211
    Keywords: Key words Amphibian ; Axolotl ; Ikaros ; Hematopoiesis ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  TheIkaros family of transcription factors plays an essential role in hematopoiesis. We report here the structure of cDNA clones encoding two Ikaros isoforms, Ik1 and Ik2, in the Mexican axolotl. The Ik1 cDNA sequence is very similar to that of the rainbow trout, chicken, and mammalian Ik1 sequences. However, a 96 base pair region which encodes the first N-terminal zing finger (F1) is lacking from axolotl Ik1, both in clones from a cDNA library and clones isolated from direct polymerase chain reaction products. A region corresponding to exon 3 is completely absent from the axolotl Ik2 sequence and thus the Ik1 and Ik2 isoforms possess the same number of zinc finger motifs. The structure of these five CC-HH motifs is very well conserved in the axolotl, including the structural deviations from its amino acid consensus composition which are identical in all species analyzed to date. The axolotl Ik1 3′ untranslated region sequence is very long (2538 bp) and contains two UA-rich motifs known as instability determinants and which could play a role in mRNA translational efficiency. Ikaros transcripts are first detected in the ventral blood island of stage 36 embryos, about 24 h before the first heartbeats (late tailbud stage), and then in the major lymphopoietic organs of the developing larvae. In situ hybridization demonstrates that Ikaros transcripts are abundant at the periphery of the thymus lobes, in the presumptive site of early thymocyte differentiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050610
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Wide tissue distribution of axolotl class II molecules occurs independently of thyroxin (1998)
    Springer
    Immunogenetics 47 (1998), S. 339-349 
    Details
    ISSN: 1432-1211
    Keywords: Key words Axolotl ; Salamander ; Metamorphosis ; Development ; Class II
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Unlike most salamanders, the Mexican axolotl (Ambystoma mexicanum) fails to produce enough thyroxin to undergo anatomical metamorphosis, although a “cryptic metamorphosis” involving a change from fetal to adult hemoglobins has been described. To understand to what extent the development of the axolotl hemopoietic system is linked to anatomical metamorphosis, we examined the appearance and thyroxin dependence of class II molecules on thymus, blood, and spleen cells, using both flow cytometry and biosynthetic labeling followed by immunoprecipitation. Class II molecules are present on B cells as early as 7 weeks after hatching, the first time analyzed. At this time, most thymocytes, all T cells, and all erythrocytes lack class II molecules, but first thymocytes at 17 weeks, then T cells at 22 weeks, and finally erythrocytes at 26–27 weeks virtually all bear class II molecules. Class II molecules and adult hemoglobin appear at roughly the same time in erythrocytes. These data are most easily explained by populations of class II-negative cells being replaced by populations of class II-positive cells, and they show that the hemopoietic system matures at a variety of times unrelated to the increase of thyroxin that drives anatomical metamorphosis. We found that administration of thyroxin during axolotl ontogeny does not accelerate or otherwise affect the acquisition of class II molecules, nor does administration of drugs that inhibit thyroxin (sodium perchlorate, thiourea, methimazole, and 1-methyl imidazole) retard or abolish this acquisition, suggesting that the programs for anatomical metamorphosis and some aspects of hemopoietic development are entirely separate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050368
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    A photosensitive circadian oscillator in an insect endocrine gland: photic induction of rhythmic steroidogenesis in vitro (1998)
    Springer
    Journal of comparative physiology 182 (1998), S. 343-349 
    Details
    ISSN: 1432-1351
    Keywords: Key words Pacemaker ; Entrainment ; Ecdysteroids ; Prothoracicotropic hormone ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The paired prothoracic glands of the insect Rhodnius prolixus each comprise a group of about 200 structurally identical cells. The synthesis (and release) of steroid moulting hormones (ecdysteroids) by these glands is under circadian control in vivo. We monitored ecdysteroid synthesis by single glands during long-term incubations in vitro. Synthesis is rhythmic in vitro and persists in continuous darkness. Glands which are arrhythmic (from prolonged continuous light) respond to transfer to darkness in vitro with the initiation of a free-running circadian rhythm of ecdysteroid synthesis. Therefore, the glands possess a light-sensitive circadian oscillator. These properties are conventionally associated with nervous tissue of animals. It is suggested that rhythmicity is synchronized within the gland by the known structural and electrical coupling between its component cells. The glands share properties with known pacemakers such as the avian pineal. However, the glands in vivo receive input from both light cues and the cerebral neuropeptide, prothoracicotropic hormone. Rhythmic release of this neuropeptide is controlled by a second oscillator located in the brain. We conclude that the pacemaker in the endocrine system of R. prolixus comprises at least three oscillators, one in each prothoracic gland and one in the brain, which are coupled hormonally. We conclude that the prothoracic gland is an important component of the circadian system controlling development in R. prolixus and that peripheral endocrine glands may play a more active role in the generation of animal circadian organization than has been thought.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050184
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    BMP/GDF-signalling interactions during synovial joint development (1999)
    Springer
    Cell & tissue research 296 (1999), S. 111-119 
    Details
    ISSN: 1432-0878
    Keywords: Key words Synovial joint ; Development ; Hyaluronan ; BMP ; GDF-5 ; Antagonists
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The synovial joint arises from an initial condensation of cells that subsequently develops into distinct skeletal structures, separated by the joint. Bone morphogenetic proteins (BMPs) and growth and differentiation factors (GDFs) have a fundamental role during skeletogenesis, including joint formation. Development of the joint appears to be dependent on the differential expression/activity of the related BMP and GDF subfamilies. Gdf-5 is expressed in the developing joints and is necessary for the formation of some joints. In contrast, recent data has shown that antagonism of the BMP family is crucial for joint formation. Here, we review mechanisms of how BMP signalling may be antagonised/modified. We also describe the expression of Bmp-2 and Bmp-4 together with two BMP antagonists, chordin and noggin, during chick joint development. Finally, we discuss possible mechanisms of how a joint forms and the evidence that the joint is a ’signalling centre’ that may coordinate the development of adjacent skeletal structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051272
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Intestinal enzymes activities in isolated villus and crypt cells during postnatal development of the rat (1977)
    Springer
    Cell & tissue research 176 (1977), S. 167-178 
    Details
    ISSN: 1432-0878
    Keywords: Intestine (rat) ; Development ; Isolated cells ; Enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A modification of Weiser's (1973) cell isolation method was used in order to study the developmental pattern of various intestinal enzyme activities in villus and crypt cells of normal rats from 5 days after birth until 8 weeks. Alkaline phosphatase and enterokinase activities were always located in the upper villus zone during postnatal development. Enterokinase activity was higher in the upper villus cells during the third week of life than after this period. Aminopeptidase activity was located in the crypt cells during the first week, its maximum activity remained in this area until the third week. At this time, sucrase activity appeared in the crypt cells, then aminopeptidase and sucrase activities rose to the villus zone during the fourth week. Amylase activity was detected along the entire crypt-villus axis 5 days after birth, reaching maximum activity in crypt cells at the end of the first week and in the upper villus cells after the fourth week. In contrast with the other enzymes studied almost all amylase activity was soluble in the youngest animals whereas at weaning most of the activity appeared in a particulate form in the villus cells. But in the crypt cells the ratio between particulate and soluble form remained unchanged until the adult stage. Various hypotheses are advanced to explain the patterns of evolution of the different enzymes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229460
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Scanning electron microscopy of dissociated pancreatic acinar cell surfaces (1977)
    Springer
    Cell & tissue research 176 (1977), S. 493-504 
    Details
    ISSN: 1432-0878
    Keywords: Pancreas ; Acinar cells ; Cell surface ; Dissociation ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pancreatic acinar cell surfaces have been studied by SEM with a dissection technique and correlated with results obtained by TEM. The SEM results demonstrate characteristic arrangement of microplicae which in some areas are densely packed. In many areas, the microplicae are distributed in such a manner that they create zones with typical geometrical shapes and show a relatively smooth surface. These smooth areas may coincide, as indicated by correlated TEM results, with the limits of intimate contact between adjacent acinar cells which, in turn, represent part of the junctional complex. Another aspect revealed by these SEM preparations concerns the presence of groups of densely packed microplicae, arranged in regular rows and distributed along some grooves and/or infoldings of the cellular surface. On the basis of SEM and TEM information, it is likely that these structures correspond to intercellular (and possibly, in some cases, intracellular) canaliculi which topographically form a kind of extensive microlabyrinthine arrangement running along all the cell sides. One final point revealed by fractured samples concerns the finding of spherical zymogen droplets within the vesicles of the Golgi complex. Because in many scanning images these vesicles appear connected by small openings, it is suggested that they may represent a system of intercommunicating chambers (vacuoles) through which the zymogen droplets can be continuously accumulated and discharged into the acinar lumen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231404
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    The third ventricle of monkeys (1977)
    Springer
    Cell & tissue research 177 (1977), S. 307-316 
    Details
    ISSN: 1432-0878
    Keywords: Third ventricle ; Mature monkeys ; Scanning electron microscopy ; Ependyma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Surface features of the ependymal lining of the third ventricle in mature male and female monkeys have been investigated with scanning electron microscopy (SEM). Broad aspects of third ventricular morphology from three species of monkey are similar regardless of sex. The lateral walls are heavily ciliated whereas the ventral floor and most ventral parts of the lateral walls are not. Clumps of cilia on the lateral walls are so dense that underlying surface details are usually obscured. There is a transition zone between the ciliated lateral wall and nonciliated ventral floor. The floor and lower part of the lateral walls of the third ventricle exhibit a characteristic polygonal pattern upon which surface specializations such as microvilli, blebs and polymorphous membrane protrusions are superimposed. Ependyma of the choroid plexus of the third ventricle also display membrane specializations. Supraependymal cells are more visible in nonciliated regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Development of the olfactory organ in the rainbow fish Nematocentris maccullochi (Atheriniformes, Melanotaeniidae) (1979)
    Springer
    Cell & tissue research 200 (1979), S. 53-68 
    Details
    ISSN: 1432-0878
    Keywords: Olfactory organ ; Development ; Melanotaeniidae ; Scanning and transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the olfactory organ in the rainbow fish, Nematocentris maccullochi, was studied using scanning and transmission electron microscopy; it was compared with the developmental process in other teleosts, especially in the closely related atherinids and cyprinodonts. The formation of the nares parallels that in atherinids, salmonids, cyprinids and heterosomats, but differs from that found in cyprinodonts. Another ontogenetic feature in which the olfactory organs of the rainbow fish and also of atherinids differ from those of cyprinodonts, is the occurrence of transitory kinociliary cells which disappear during the postlarval period. The divergent evolutionary pathways are discussed with reference to experimental investigations. During development, ciliated and microvillous receptor cell types occur. At the primary larval stage ciliated receptor neurons are exclusively present. At a later stage the microvillous type develops and becomes equal in frequency. Thus, the microvillous receptor represents a separate type of olfactory neuron and is not a progenitor of the ciliated receptor cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236887
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Muscle development during vertebrate limb outgrowth (1999)
    Springer
    Cell & tissue research 296 (1999), S. 131-139 
    Details
    ISSN: 1432-0878
    Keywords: Key words Limb ; Development ; Myogenesis ; Vertebrate ; Transcription factors ; Somites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Limb development has become one of the model systems for studying vertebrate development. One crucial aspect in limb development is the origin, differentiation and patterning of muscle. Much progress has been made in recent years towards understanding this process. One of the general observations is that the genes involved in limb muscle development appear to be very similar to those involved in muscle development in other regions of the embryo. In this review, we summarize some of the genes and mechanisms that regulate limb muscle development and discuss various avenues along which a deeper understanding can be gained of how muscle cells originate and differentiate in different tissues during vertebrate development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051274
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Three-dimensional development of luminal projections and junctional complexes in the developing central nervous system blood vessels of the rat (1977)
    Springer
    Cell & tissue research 175 (1977), S. 541-549 
    Details
    ISSN: 1432-0878
    Keywords: Blood vessels ; High voltage electron microscopy ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The luminal surface features and Junctional complexes from developing blood vessels in the rat central nervous system have been studied by high-voltage electron microscopy and scanning electron microscopy. Developing blood vessels exhibit three types of luminal projections; marginal folds or ridges at Junctional complexes, ridges not at Junctional complexes and microvilli. Both types of ridges are associated with troughs or depressions in the luminal surface of the endothelial cell. Those ridges not associated with Junctional complexes take part in the production of enclosed tunnels in the endothelial cell cytoplasm. Fusion of the external leaflets of Junctional complexes between adjacent endothelial cells occurred, initially, near the luminal surface of the blood vessel with other small fusion sites forming in the direction of the basal lamina secondarily. Further fusion activity to produce the zonula occludens type junction appeared to spread outwards from the smaller fusion sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222417
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Classification of human placental villi (1979)
    Springer
    Cell & tissue research 200 (1979), S. 409-423 
    Details
    ISSN: 1432-0878
    Keywords: Human placenta ; Classification of villi ; Histology ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The classification of human placental villi was reviewed on the basis of material prepared by means of special methods. The material from in situ normal-term placentae was biopsied by aspiration into glutaraldehyde. The classification was made on the basis of light-microscopic observations of semithin sections, reconstructions from serial sections, and scanning-electron micrographs. The peripheral villous tree is roughly divided into stem (ramuli), intermediate and terminal villi. The intermediate villi may be further subdivided as mature and immature types, which are found between the stem and terminal villi. Some of the terminal villi possess a local specialization described as the neck region. The histological characteristics and the branching pattern of each type are described, and the basis of the proposed classification is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234852
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Hox genes in digit development and evolution (1999)
    Springer
    Cell & tissue research 296 (1999), S. 19-25 
    Details
    ISSN: 1432-0878
    Keywords: Key wordsHoxA ; HoxD ; Limb ; Development ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Homeobox genes located in the 5’ part of the HoxA and HoxD complexes are required for proliferation of skeletal progenitor cells of the vertebrate limb. Specific combinations of gene products determine the length of the upper arm (genes belonging to groups 9 and 10), the lower arm (groups 10, 11 and 12) and the digits (groups 11, 12 and 13). In these different domains, individual gene products quantitatively contribute to an overall protein dose, with predominant roles for groups 11 and 13. Quantitative reduction in the gene dose in each set results in truncations of the corresponding anatomical regions. The physical order of the genes in the HoxA and HoxD complexes, as well as a unidirectional sequence in gene activation, allow for completion of the process in a precise order, which in turn makes possible the sequential outgrowth of the respective primordia. While the skeletal patterns of upper and lower limb are relatively stable throughout the tetrapods, more variation is seen in the digits. Molecular analysis of the underlying regulatory processes promises further exciting insights into the genetic control of development, pathology and the course of evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051262
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    From head to toe: conservation of molecular signals regulating limb and craniofacial morphogenesis (1999)
    Springer
    Cell & tissue research 296 (1999), S. 103-109 
    Details
    ISSN: 1432-0878
    Keywords: Key wordsgli3 ; Ωtalpid ; extra-toes ; Sonic hedgehog ; Retinoic acid ; Development ; Birth defects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Recent evidence indicates that many molecules involved in generating and patterning the limbs also play a role during craniofacial morphogenesis. On the surface, this is an unexpected finding given that these regions of the body have separate evolutionary origins, are composed of different embryonic tissues, and are quite dissimilar in their anatomy. Results from several experiments involving Sonic hedgehog and retinoic acid point to a remarkable conservation of the signaling pathways mediated by these morphogens across multiple organ systems. Moreover, mutants such as the extra-toes and doublefoot mouse, and the talpid chicken also provide insights on common developmental processes that underlie the formation of the limbs and face. The identification of highly conserved aspects of morphogenesis is important for understanding fundamental mechanisms of development, as well as for revealing the common denominator of countless birth defects and providing new strategies for their prevention and cure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051271
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Photoreceptor-like outer segments in the pineal organ of the lovebird, Uroloncha domestica (Aves: Passeriformes) (1977)
    Springer
    Cell & tissue research 182 (1977), S. 139-143 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Uroloncha domestica (Aves, Passeriformes) ; Photoreceptor-like cells ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the pineal organ of the lovebird, Uroloncha domestica, bulbous, cup-shaped and elongated outer segments of photoreceptor-like pinealocytes are demonstrated by scanning electron microscopy. These scarce outer segments, 4–11 μm in length, extend into the pineal lumen. The present structural observations speak in favor of photosensitive pinealocytes in the pineal organ of Uroloncha domestica. The relation of the photoreceptor-like pinealocytes to acetylcholinesterase-positive nerve cells and a nervous connection between the pineal and the brain indicate that the pineal organ of this passeriform species may be the site of neuroendocrine and photoreceptive functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222062
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Morphogenesis of tight junctions in the peritoneal mesothelium of the mouse embryo (1979)
    Springer
    Cell & tissue research 198 (1979), S. 247-260 
    Details
    ISSN: 1432-0878
    Keywords: Tight junctions ; Development ; Mesothelium ; Mouse embryo ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The peritoneal mesothelium of mouse embryos (12 to 18 day of gestation) was studied by freeze-fracture and in sections in order to reveal the initial formation of the tight junctions. Freeze-fracture observations showed three types of tight junctions. Type I consists of belt-like meshworks of elevations on the P face and of shallow grooves on the E face. No tight junctional particle can be seen either on the elevations or in the grooves. Type II shows rows of discontinuous particles on the elevations on the P face. Type III consists of strands forming ridges on the P face. On the E face, the grooves of Type II and III appear to be narrower and sharper than those of Type I. Quantitatively, Type I junctions are most numerous during the early stages (day 12–13) of embryonic development, while Type III junctions become more common in the later stages, and are the only type seen by day 18. Observations on sections, however, fail to distinguish between the three types. The results suggest that an initial sign of tight junction formation is close apposition of the two cell membranes in the junctional domain, without tight junctional particles. Later, the particles appear to be incorporated in the tight junctions and the strands form by fusion of the particles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232008
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Development of the axon cap neuropil of the Mauthner cell in the goldfish (1984)
    Springer
    Cell & tissue research 237 (1984), S. 49-55 
    Details
    ISSN: 1432-0878
    Keywords: Axon ; Synapses ; Medulla oblongata ; Gold-fish ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Development of the axon cap neuropil of the Mauthner neuron in post-hatching larval goldfish brains was observed electron-microscopically. The axonal initial segment of newly hatched (day-4) larvae is completely covered with synaptic terminals containing clear spherical synaptic vesicles. Profiles of thin terminal axons, the spiral fibers, containing similar synaptic vesicles, rapidly increase in number around the initial segment and form glomerular neuropil similar to the central core of the adult axon cap by day 7. Three types of synapses are formed in the core neuropil. Bouton-type synapses contacting the initial segment are most abundant in day-4 to-14 larvae; they decrease thereafter and are rare on the distal half of the initial segment of day-40 larvae. Asymmetric axo-axonic synapses are commonly observed between spiral fibers in the core neuropil of day-7 to -19 larvae, but become fewer by day 40. Unique symmetrical axo-axonic synapses showing accumulation of synaptic vesicles on either side of apposed membrane thickenings first appear in day-14 core neuropil, gradually increase in number, and become the predominant type in day-40 core neuropil. Thick myelinated axons, which lose their myelin sheaths in the glial cap cell layer, start to penetrate into the axon cap on day 10. They gradually increase in number and form the peripheral part of the axon cap together with the cap dendrites, which finally grow into the axon cap from the axon hillock region of the Mauthner cell by day 40.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229199
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Topographical and developmental studies on target sites of 1,25 (OH2) vitamin D3 in skin (1984)
    Springer
    Cell & tissue research 238 (1984), S. 489-496 
    Details
    ISSN: 1432-0878
    Keywords: Vitamin D ; Skin ; Autoradiography ; Hair ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tritium-labeled 1,25 (OH2) vitamin D3, when injected into vitamin D-deficient adult and pregnant rats is concentrated and retained strongest in nuclei of cells in the outer root sheath of the hair, followed by the stratum granulosum, spinosum, and basale of the epidermis. In the hair follicle, in addition to the most heavily labeled outer root sheath, nuclear labeling exists also in cells of the hair bulb and of the inner root sheath, as well as in basal cells of the sebaceous gland. In contrast, cells of the dermal papilla and the connective tissue of the dermis are generally unlabeled, except for labeled cells in the outer connective tissue sheath at the infundibulum of vibrissae of 20-day fetal rats and a few scattered labeled cells in the dermis, probably macrophages. In the developing hair, in 18- and 20-day fetal rats, a distinct topographic pattern of labeled cells can be seen, which is characteristic of the different stages of hair follicle development. In the hair germ, heavily labeled cells appear first in the stratum spinosum. In the hair peg, they remain in this position in its juxtaepidermal portion; however, when a dermal papilla develops, heavily labeled cells assume a marginal position. This suggests a sequential epidermal-epidermal and mesenchymal-epidermal receptor induction. Injection of tritium labeled 25 (OH) vitamin D3 did not show nuclear concentration in these tissues and excess unlabeled 25 (OH) vitamin D3 — unlike excess 1,25 (OH2) vitamin D3 — did not prevent nuclear uptake of tritium labeled 1,25 (OH2) vitamin D3. The results indicate differential effects of 1,25 (OH2) vitamin D3 on different structures in the epidermis and dermis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219863
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    The salivary glands of the cockroach Nauphoeta cinerea (Olivier) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 525-534 
    Details
    ISSN: 1432-0878
    Keywords: Salivary glands ; Insects ; Innervation ; Light microscopy ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the salivary gland of the cockroach Nauphoeta cinerea (Olivier) has been investigated with the use of light and scanning electron microscopy. Light microscopy of methylene blue stained glands reveals the presence of a dual innervation arising from the ventral nerve cord and the stomodeal nervous system; the principal innervation is that from the ventral nerve cord which passes to the gland via the reservoir ducts. Branches of these nerves form a plexus on the acinar surface, the axons of which exhibit swelling at irregular intervals. The presence of this surface plexus and the axonal swellings was confirmed by scanning electron microscopy both in normal glands and in those in which the basal lamina had been removed by means of an HCl-collagenase digestion method. No acinar plexus was seen to be formed by branches of the stomatogastric nerve that were associated with the gland. However, other branches of this nerve were clearly connected with a complex network of multipolar neurones on the surfaces of the anterior regions of both salivary reservoirs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229617
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    The mature mesonephric nephron of the rabbit embryo (1980)
    Springer
    Cell & tissue research 209 (1980), S. 95-109 
    Details
    ISSN: 1432-0878
    Keywords: Mesonephric nephron ; Scanning electron microscopy ; Rabbitembryo ; Wolffian body
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The luminal surface ultrastructure of the mature mesonephric nephron in 18 day rabbit embryos was studied in order to classify the nephron segments and to compare them with their metanephric counterparts. The proximal tubule has two slightly different segments. Its brush-bordered cells, with lateral ridges and basal microvilli (revealed in disjoined cells) exhibit structural principles similar to those of metanephric cells. The short distal tubule, starting with an abrupt border, cannot be subdivided. Its surface differs from one specimen to the next; the various cellular patterns are regarded as different functional states rather than evidence of a true cellular heterogeneity. Cells with leaf-like meandering borders correspond to similar metanephric cells favoring a paracellular transport mechanism. The collecting tubule shares common features with the metanephric collecting duct in spite of its different origin. Among principal cells, clearly demarcated by marginal microvillous rows and studded with sparse apical microvilli, non-ciliated and strongly bulging intercalated cells occur in small numbers. The latter have exaggerated, sometimes branched microvilli, and occasional microplicae. In the Wolffian duct, which has no metanephric counterpart, the single cilia dominate the picture of a homogeneous cell population. Apical globular protrusions of the tubular epithelia, which have been depicted in almost every paper on the mesonephros, are all fixation artefacts that can only be avoided by properly perfusing the living embryo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219926
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Origin of the glial processes responsible for the spontaneous postnatal phagocytosis of boutons on cat spinal motoneurons (1978)
    Springer
    Cell & tissue research 189 (1978), S. 203-217 
    Details
    ISSN: 1432-0878
    Keywords: Astrocytes ; Development ; Phagocytosis ; Neuroplasticity ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previous studies have demonstrated that astrocyte processes are responsible for a spontaneously occurring phagocytosis of boutons on cat spinal motoneurons during the second postnatal week. In the present investigation, the astrocytes and the astrocyte processes in contact with the motoneurons were studied qualitatively and quantitatively during the early postnatal period. It could be concluded that the cells responsible for the phagocytosis of boutons are immature astrocytes. These cells were present not only during the period of phagocytosis but also prior to this period. The type of process responsible for the phagocytosis was present not only during the period of phagocytosis but also prior to and after that period although the relative contribution of such processes to the glia-covered membrane area of the motoneurons was reduced in the older animals. On the basis of these results, the possible specificity of the immature astrocyte as the element responsible for the phagocytosis of boutons during normal development is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209270
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    The human rete testis (1978)
    Springer
    Cell & tissue research 189 (1978), S. 409-433 
    Details
    ISSN: 1432-0878
    Keywords: Rete testis ; Human ; Histophysiology ; Chordae retis ; Scanning electron microscopy ; Transmission electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The human rete testis was examined with regard to 1) the number and distribution of entrances of seminiferous tubules, 2) the light microscopic topography and 3) details of the passages as revealed by scanning and transmission electron microscopy. In a newborn 1474 entrances were counted, approximately 50 % entering from the right and 50 % from the left of the central long axis. Three major subdivisions of the rete were distinguished and described: a septal (or interlobular) part represented by tubuli recti, a tunical (or mediastinal) part which is a true network of channels, and an extratesticular part characterized by dilatations (up to 3 mm wide) which we have called bullae retis. In SEM, cylindrical strands running from wall to wall in the tunical and extratesticular rete spaces are a prominent feature. We have called these chordae retis. They are covered by epithelium and are 5–40 μm wide and 15 to more than 100 μm long. They contain a peculiar tissue consisting of central myoid cells in a fibroelastic matrix. The smaller chordae are avascular. In the light of these findings the rete is interpreted as a highly complex myoelastic sponge. Its function is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Model of skin vascularization in Rana esculenta L.: Scanning electron microscopy of microcorrosion casts (1978)
    Springer
    Cell & tissue research 191 (1978), S. 539-548 
    Details
    ISSN: 1432-0878
    Keywords: Frog skin ; Respiratory capillaries ; Capillary networks ; Microcorrosion casts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Microcorrosion casts of blood vessels in the skin of Rana esculenta L. were examined by means of scanning electron microscopy with particular reference to the subepidermal network of respiratory capillaries. Due to the fact that arteries and veins lie in the deeper layers of the stratum spongiosum of the corium, the respiratory vessels form a morphologically homogeneous network. Functionally, however, this network is subdivided into small areas with a centripetal direction of blood flow. The deep capillary net, situated at the base of the stratum compactum of the corium, is not so dense as the respiratory network and does not directly communicate with it. Alveolar glands of the skin have no effect on the distribution of capillaries in the two networks.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219816
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Scanning electron microscopy of peripheral blood leukocytes of the chicken (1979)
    Springer
    Cell & tissue research 204 (1979), S. 147-153 
    Details
    ISSN: 1432-0878
    Keywords: Granulocytes ; Lymphocytes ; Monocytes ; Scanning electron microscopy ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Polymorphonuclear leukocytes, e.g., neutrophilic granulocytes, were enriched from heparinized blood by a Ficoll-step-gradient centrifugation procedure. Scanning electron microscopy (SEM) revealed a surface morphology of narrow ridge-like profiles and small ruffles with occasional microprocesses. Mononuclear leukocytes were isolated by centrifugation over a Ficoll-Metrizoat gradient. The lymphocytes showed varying numbers of microvilli of different length, size and shape. B lymphocytes, characterized by their capability of “sheep red blood cell (SRBC)-rosette formation”, displayed a similar surface morphology. Completely smooth lymphocytes, described in the literature as T lymphocytes, could not be detected, although many lymphocytes with few microprocesses were observed. Thus, SEM is not a useful tool for distinguishing between B and T lymphocytes in the peripheral blood of chickens. Monocytes were characterized by prominent membrane-like ruffles, but in some cases they closely resembled granulocytes. An influence of the various separation media on the surface morphology of the isolated cells could not be detected when compared with cells isolated by the buffy-coat method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235171
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Prenatal and early postnatal development of the glial cells in the median eminence of the rat (1980)
    Springer
    Cell & tissue research 211 (1980), S. 117-137 
    Details
    ISSN: 1432-0878
    Keywords: Eminentia mediana ; Neurohypophysis ; Development ; Pituicytes ; Tanycytes ; Astrocytic tanycytes ; Oligodendrocytes ; Astrocytes ; Microglia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the glial cells of the rat median eminence (ME), including the supraependymal cells, was investigated from embryonic day (ED) 14 through postnatal day (PD) 7, and pituicyte development from ED 12 through ED 17. The anlage of the ME and neurohypophysis shows a neuroepithelial-like structure at ED 12. From ED 13 to 15, the cells of both regions start to differentiate. At the ultrastructural level, only one cell type appears. At the beginning of ED 16, glioblasts of the oligodendrocyte and astrocyte series migrate laterally (from the region of the arcuate nucleus) into the ME. Also at this time the first distinctive structural features appear in the neurohypophysial anlage, the cells of which later develop into pituicytes. Starting at ED 18, tanycytes and astrocytic tanycytes arise in the ME from local glial cells, and somewhat later oligodendroblasts and astroblasts are formed from immigrant glioblasts. Due to their common features, the pituicytes, tanycytes and astrocytic tanycytes apparently represent different forms of the same parent cell type. Microglial and supraependymal cells are first seen at ED 12. Initially, they resemble the prenatal phagocytic connective tissue cells and mature in the fetus into typical electron-dense microglia and macrophage-like supraependymal cells. Both cell types are apparently of mesodermal origin. The microglial elements of the ME probably migrate from the mesenchyma through the basement into the nervous tissue. The intraventricular macrophages of the infundibular region may originate from microglia, epiplexal cells and subarachnoid macrophages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233728
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Postnatal development of somatotrophs and mammotrophs in the pars distalis of the C57BL mouse (1980)
    Springer
    Cell & tissue research 211 (1980), S. 441-448 
    Details
    ISSN: 1432-0878
    Keywords: Somatotroph ; Mammotroph ; Development ; Mouse ; Pituitary
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pars distalis of the pituitary gland of the C57BL mouse was studied by means of electron microscopy during postnatal stages of males ranging in age from newborn through 24 days, with particular emphasis on the somatotrophs and mammotrophs. During this period, growth curves were plotted in order to correlate postnatal growth patterns with the state of differentiation of the somatotrophs in the pars distalis. In the newborn, the somatotrophs show well developed organelles, including rough endoplasmic reticulum and Golgi complexes. These cells are not as densely packed with granules as the adult somatotrophs; however, from days 5 through 24, they show a progressive accumulation of granules. Although mammotrophs are scarce in the newborn, they are readily distinguishable in the pars distalis at 5 days. Male mice in small litters show a progressive increase in body weight between birth and 11–12 days, at which time the rate slackens until 18–19 days when the rate again increases. Growth curves for mice from large litters are similar to those from smaller litters, except that the transitory decrease in rate is more prominent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234398
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Transient axonal side branches in the developing mammalian optic nerve (1997)
    Springer
    Cell & tissue research 291 (1997), S. 43-56 
    Details
    ISSN: 1432-0878
    Keywords: Key words Optic axons ; Axon navigation ; Growth cones ; Development ; Mammals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Optic axons were labelled with horseradish peroxidase to establish the presence of side branches and examine their distribution and morphology in the developing optic nerve of the quokka wallaby, Setonix brachyurus, the cat and rat at stages when axon numbers are at their peak. In each species, three quarters of the axons were essentially straight and lacked side branches. The remaining axons took significantly longer paths and bore side branches, mostly at points where axons undulated or changed direction. Side branches occurred at intervals of 28–43 µm, had lengths of 2–3 µm and were usually simple rather than branched. A minority (1%) of the axons crossed diagonally between fascicles and two thirds of these had more side branches (interval: 10–18 µm) on the interfascicular portion than were found on the forward-directed axons. A small number of axons (0.01%) doubled back to grow retrogradely towards the eye, these axons also bore relatively more side branches (interval: 8–22 µm), especially at points where the axons changed direction. Ultrastructural reconstruction showed that side branches resembled small axonal profiles and constituted 2% of the total axon number. It is suggested that side branches are involved in the fine-tuning of growth cone navigation. Most side branches are lost by adulthood, indicating their transient nature. The absence of retrogradely-directed axons from adults suggests that cells with such axons are removed by naturally occurring cell death.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050978
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Calbindin D28k-like immunoreactivity in the developing and regenerating circumvallate papilla of the rat (1997)
    Springer
    Cell & tissue research 291 (1997), S. 81-90 
    Details
    ISSN: 1432-0878
    Keywords: Key words Calbindin D28k ; Circumvallate papilla ; Taste buds ; Development ; Degeneration ; Regeneration ; Immunohistochemistry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The distribution of calbindin D28k (CB)-like immunoreactivity (-LI) in the circumvallate papilla (CVP) was examined during development and regeneration following bilateral crush injury to the glossopharyngeal nerve in the rat. In the adult CVP, CB-like immunoreactive (-IR) nerve fibers were observed in the subgemmal region and some penetrated into the taste buds. CB-LI was also detected in the cytoplasm of the spindle-shaped gustatory cells in the lower half of the trench epithelium, which contained numerous synaptic vesicles and bundles of intermediate filaments. These CB-IR gustatory cells made synapse-like contacts with CB-IR nerve terminals. Some CB-IR nerve terminals made contacts with the gustatory cells negative for CB-LI. At least three developmental stages were defined with regard to the developmental changes in the distribution of CB-LI: (1) Stage I (embryonic day (E) 18–postnatal day (P)5): CB-IR nerve fibers appeared in the lamina propria just beneath the newly-formed CVP at E18, but the gustatory epithelium of the CVP contained no CB-IR structures. Taste buds with taste pores appeared at P1. (2) Stage II (P5–10): thin CB-IR nerve fibers began entering the trench epithelium, but no CB-IR cells were observed. (3) Stage III (P10–adult): in addition to the intragemmal and perigemmal CB-IR nerve fibers, very few CB-IR cells appeared in the taste buds around P10, and their numbers increased progressively. The changes in the distribution of taste buds and CB-LI following glossopharyngeal nerve injury were similar to those observed during development. On post-operative day (PO) 4, the taste buds and CB-IR cells decreased markedly in number. These CB-IR cells became round in shape, and the number of CB-IR nerve fibers decreased markedly. On PO8, both taste buds and CB-IR cells disappeared completely. The regenerated taste buds were first observed on PO12, increased rapidly in number by PO20, and increased slowly thereafter. CB-IR nerve fibers accumulated at the subgemmal region and began penetrating into the trench wall epithelium around PO16. CB-IR cells appeared between PO20 and PO24, and their numbers increased progressively and reached the normal level on PO40. The topographical localizations of the taste buds and CB-IR cells during development and regeneration were comparable to those of normal animals. The delay of the time courses for appearance of CB-IR nerve fibers and CB-IR cells compared to the appearance of taste buds during development and regeneration suggests that CB in the gustatory epithelium may participate in the survival of the taste bud cells rather than in the induction of the taste buds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050981
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Ciliary neurotrophic factor blocks rod photoreceptor differentiation from postmitotic precursor cells in vitro (1998)
    Springer
    Cell & tissue research 291 (1998), S. 207-216 
    Details
    ISSN: 1432-0878
    Keywords: Key words CNTF ; Photoreceptor ; Retina ; Development ; Differentiation ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The development of photoreceptors in the mammalian retina is thought to be controlled by extrinsic signals. We have shown previously that ciliary neurotrophic factor (CNTF) potently inhibits photoreceptor differentiation in cultures of rat retina. The present study analyzes which developmental processes are affected by CNTF. Rod differentiation as determined by opsin and recoverin immunocytochemistry was effectively blocked by CNTF and leukemia inhibitory factor, but not by other neurotrophic agents tested. CNTF did not influence proliferation, cell death, or survival, and had no effect on the downregulation of nestin immunoreactivity in progenitor cells. Opsin-positive rods could be reverted to an opsin-negative state initially, but became unresponsive to CNTF later. No compensatory increase in the number of other cell types was observed. Application of neutralizing antibodies against CNTF revealed that rod development was partially blocked by an endogenous CNTF-like molecule in control cultures. Our results suggest that CNTF can act as a specific negative regulator of rod differentiation. Its action on photoreceptor precursor cells could serve to synchronize the maturation of photoreceptors, which are born over an extended period of time. Together with other stimulatory signals, CNTF may thus control the temporally and numerically correct integration of photoreceptors into the retinal network.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050991
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Changing patterns of spatial buffering of glutamate in developing rat retinae are mediated by the Müller cell glutamate transporter GLAST (1999)
    Springer
    Cell & tissue research 297 (1999), S. 57-66 
    Details
    ISSN: 1432-0878
    Keywords: Key words D-aspartate ; Development ; Glutamate ; Retina ; Glutamate transporter (GLAST) ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The patterns of expression of the glutamate transporter GLAST were compared with the patterns of uptake of exogenous D-aspartate, which is a substrate for all glutamate transporters. At postnatal day 0, fine radial processes and end feet of presumptive Müller cells were weakly immunoreactive for GLAST. At postnatal day 3, intense labelling was associated with astrocytes enveloping newly formed blood vessels on the vitread surface of the retina. Between postnatal days 7 and 10, there was a rapid increase in the intensity of labelling in the Müller cells but clear stratification of GLAST-immunoreactive processes in the inner plexiform layer was not observed until postnatal day 14. By comparison, D-aspartate uptake was initially associated with a wide variety of cellular elements including most neuroblasts, presumptive Müller cells, and astrocytes associated with blood vessels but was absent from the somata of many neurons in the ganglion cell layer and amacrine cell layer. There was a gradual contraction in the numbers of cells that were able to take up D-aspartate, such that, by adulthood, uptake was restricted mainly to Müller cells and astrocytes. We conclude that, during early retinal development, the low levels of GLAST expression by Müller cells permit D-aspartate, and by inference, glutamate, to permeate the retina freely, thus allowing uptake by other glutamate transporters on other cell types. As the retina matures, increased expression of GLAST by Müller cells restricts the access of D-aspartate to other cellular compartments in the retina. This changing pattern of spatial buffering of glutamate by GLAST probably has significant implications regarding our understanding of the role of glutamate during processes such as retinal synaptogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051333
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Expression of cystatin-related protein and of the C3-component of prostatic-binding protein during postnatal development in the rat ventral prostate and lacrimal gland (1998)
    Springer
    Cell & tissue research 292 (1998), S. 115-128 
    Details
    ISSN: 1432-0878
    Keywords: Key words Prostate ; Lacrimal gland ; Androgen-regulated gene expression ; Development ; In situ hybridisation ; Cystatin-related protein ; Prostatic-binding protein ; Rat (wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The expression of cystatin-related protein (CRP) and of the C3-component of prostatic-binding protein (PBP) during postnatal development of the rat was studied by Northern blotting, dot blot and in situ hybridisation, and by radioimmunoassay or immunoblotting. In intact male rats, very little or no PBP-C3 could be detected in the prostate at 10 days, but at 20 days there was already strong expression. By in situ hybridisation, the first expression of C3 mRNA was observed at 13 days in the prostate and at 22 days in the lacrimal gland. For CRP, this occurred at 16 and 22 days, respectively. Neither CRP nor C3 was expressed in prepubertal male rats castrated at day 1 or day 10 or in female rats. Androgen treatment of intact male animals did not advance the expression of both mRNAs in the prostate, but did so in the lacrimal gland with first expression of C3 at 19 instead of 22 days and of CRP at 13 instead of 22 days. Identical values were obtained in female rats. Androgen treatment of castrated adult male rats resulted in a more rapid and homogeneous secondary induction. Positive immunostaining for the androgen receptor (AR) was observed in the lacrimal gland at 7 days, but its concentration, estimated by immunoblotting, was still low at 10 days. Maximal levels, reached at 30 days, were markedly higher in male than in female rats. In conclusion, CRP and C3 are induced by androgens in prepubertal rats. The time point of induction, however, is probably determined by other tissue and differentiation-dependent factors in addition to androgens and the AR.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051041
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Adhesive activity of gicerin, a cell-adhesion molecule, in kidneys and nephroblastomas of chickens (1998)
    Springer
    Cell & tissue research 292 (1998), S. 137-142 
    Details
    ISSN: 1432-0878
    Keywords: Key words Neurite outgrowth factor ; Immunoglobulin superfamily ; Extracellular matrix ; Development ; Oncogenesis ; Kidney ; Nephroblastoma ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Gicerin, a cell-adhesion molecule belonging to the immunoglobulin superfamily, has both homophilic and heterophilic binding activities to neurite outgrowth factor, an extracellular matrix molecule in the laminin family. Gicerin is thought to play a role in the normal development of chicken kidney, because it is expressed abundantly in the embryonic organ and only slightly in the mature organ. In this study, we have examined the adhesive activity of gicerin in the kidney to characterize its function in organogenesis. We have also examined the function of gicerin in chicken nephroblastomas (“embryonic nephromas”), which show various structures resembling those in embryonic kidneys. Immunohistochemically, the expression patterns of gicerin and neurite outgrowth factor in nephroblastomas are similar to those of embryonic kidneys. Cell-aggregation assays have shown that primary culture cells from both embryonic kidneys and nephroblastomas have strong aggregation activities, and that each aggregation is partially inhibited by gicerin antibody. In contrast, cells from adult kidney exhibit weak aggregation activity that is not inhibited by the antibody. In addition, ligand blot analysis has revealed that gicerins in embryonic kidney and nephroblastoma bind to purified neurite outgrowth factor, whereas extracts from adult kidney show no positive reaction. These findings suggest that the homophilic and heterophilic adhesive activities of gicerin are involved in the formation of both normal kidney and nephroblastoma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051043
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Actin isoforms in amphioxus Branchiostoma lanceolatum (1998)
    Springer
    Cell & tissue research 292 (1998), S. 173-176 
    Details
    ISSN: 1432-0878
    Keywords: Key words Actin expression ; Monoclonal antibodies ; Development ; phylogenetic ; Branchiostoma lanceolatum (Acrania)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Actin is a highly conserved cytoskeletal protein that is ubiquitous in all eukaryotes. Little is known about actin expression in amphioxus, the closest living relative of the vertebrates. In the present study, involving Western blotting and indirect immunofluorescence, we report the characterization and localization of various actin isoforms in amphioxus (Branchiostoma lanceolatum) tissues. Three antibodies against vertebrate actins were used: a polyclonal antibody recognizing β-cytoplasmic actin (anti-β actin), a monoclonal antibody against sarcomeric actins (anti-αSR-1), and a monoclonal antibody specific for α-smooth actin (anti-αSM-1). Western blot analysis of amphioxus extracts immunodecorated with these antibodies showed a 43-kDa-positive band co-migrating with respective controls. The amphioxus isoactin expression patterns recognized by these antibodies were similar to those of vertebrates, i.e., anti-β actin showed positive staining mainly in non-muscle cells, anti-αSR-1 labelled dorsolateral myotomal muscles, and anti-αSM-1 stained ventral muscles. These results demonstrate that at least two muscle actins are present in amphioxus, suggesting that muscle actin gene duplication events began before vertebrate divergence from the amphioxus lineage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051047
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Organization of atrial natriuretic factor-like immunoreactive system in the brain of the frog Rana esculenta during development (1998)
    Springer
    Cell & tissue research 293 (1998), S. 47-55 
    Details
    ISSN: 1432-0878
    Keywords: Key words Atrial natriuretic factor ; Brain ; Development ; Rana esculenta (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Immunocytochemical distribution of the atrial natriuretic factor (ANF) has been studied in the brain and pituitary of the anuran Rana esculenta during development and in juvenile animals. Using human ANF and rat α-ANF antisera, immunoreactive cell bodies and nerve fibers were revealed in stage II–III tadpoles and in successive larval stages. Soon after hatching, stages II–III, the ANF-like-immunoreactive elements were confined to the preoptic area-median eminence complex. During successive stages of development, new groups of ANF-immunoreactive cell bodies appeared. In larval stage VI, immunoreactive perikarya were found in the rostral part of the anteroventral area of the thalamus and numerous ANF-like-immunoreactive cells appeared in the pars distalis of the pituitary. In larval stages XIV and XVIII, the distribution of ANF immunoreactivity was virtually similar. The ANF-immunoreactive cells in the preoptic nucleus and in the pituitary pars distalis were comparatively more abundant than in stage VI. During the metamorphic climax (stages XXI–XXII), a new group of ANF-immunoreactive cell bodies appeared in the rostral part of the ventrolateral area of the thalamus. During this stage, ANF-immunoreactive fiber projections were found in the pars intermedia for the first time. However, the pars distalis cells were very weakly immunofluorescent. The pattern of ANF immunoreactivity in the brain of juvenile animals was very similar to that described for stages XXI and XXII, whereas the pars distalis cells showed no immunoreactivity. It is conceivable that, early during development, ANF-related peptides may be involved in the regulation of pituitary secretion by means of autocrine mechanisms or may act as a classic pituitary hormone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051097
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Expression pattern for adrenomedullin during pancreatic development in the rat reveals a common precursor with other endocrine cell types (1998)
    Springer
    Cell & tissue research 293 (1998), S. 95-100 
    Details
    ISSN: 1432-0878
    Keywords: Key words Adrenomedullin ; Pancreas ; Development ; Immunocytochemistry ; Colocalizations ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Adrenomedullin is an α-amidated 52-amino acid peptide involved in many physiological actions, among others the regulation of insulin secretion. Using immunohistochemical methods, we found that adrenomedullin immunoreactivity first appears at day 11.5 of embryonic development in the rat, coinciding with the appearance of pancreatic glucagon. The early appearance of adrenomedullin in the developing pancreas may indicate an active involvement in either the morphogenesis of the organ or its endocrine/paracrine/autocrine hormone regulation during intrauterine life. We also investigated the pattern of colocalizations of adrenomedullin with the other pancreatic hormones. At some point during development all the cell types express adrenomedullin, progressively evolving towards the adult pattern where only the pancreatic polypeptide cells contain a strong immunoreactivity for adrenomedullin. At this point the remaining cells of the islet are, in general, weakly stained. This sequential and time-dependent expression of adrenomedullin suggests a tight regulation similar to that observed for other modulatory substances responsible for embryonic morphogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051101
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Expression of the avian VEGF receptor homologues Quek1 and Quek2 in blood-vascular and lymphatic endothelial and non-endothelial cells during quail embryonic development (1997)
    Springer
    Cell & tissue research 288 (1997), S. 207-223 
    Details
    ISSN: 1432-0878
    Keywords: Key words: VEGFR-2 ; VEGFR-3 ; Angiogenesis ; Endothelial cells ; Blood vessels ; Lymphatic vessels ; Development ; Quail embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. We have studied the expression of Quek1 and Quek2 (VEGFR-2 and VEGFR-3, respectively) in quail embryos from day 2 to day 16 by in situ hybridization with digoxigenin-labelled riboprobes on whole-mounts and paraffin sections. Parallel sections were also stained with the QH1 antibody to detect all endothelial cells and with an antibody against α-smooth-muscle-actin to reveal the media of blood vessels. Quek1/VEGFR-2 is a marker of blood-vascular and lymphatic endothelial cells throughout development. In 2-day-old embryos, it is expressed in the intra-embryonic vascular plexus, in cells (most probably angioblasts) located in the paraxial head mesoderm and in the somites, and caudo-laterally from Hensen’s node. Thereafter, until about day 9, Quek1 is expressed in all endothelial cells. Cells positive and negative for Quek1 can later be found within the same vessel. Quek1 is additionally expressed in lymphatic endothelial cells. Occasionally, some non-endothelial cell types express Quek1. Quek2/VEGFR-3 is also a marker of endothelial cells; however, its expression pattern differs from that of Quek1. In 2-day-old embryos, Quek2 is expressed in the notochord and the intra-embryonic vascular plexus. Whereas all endothelial cells are Quek2-positive in 3-day-old embryos, expression is subsequently reduced to a subset of endothelial cells: arteries become Quek2-negative and then expression of Quek2 is limited to a few vessels that appear to be lymphatic. Endothelial cells of lymph nodes and the periaortal lymphatic vessels are Quek2-positive in later stages. A few non-endothelial cells express Quek2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050807
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Localization of calcitonin gene-related peptide mRNA in developing olfactory axons (1998)
    Springer
    Cell & tissue research 294 (1998), S. 81-91 
    Details
    ISSN: 1432-0878
    Keywords: Key words Axonal mRNA ; Neuropeptide ; Olfactory pathway ; Development ; Mouse (CD1)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  During development of the olfactory pathway, calcitonin gene-related peptide (CGRP) expression is regulated both temporally and spatially. We had previous evidence that between E13 and E19 CGRP mRNA was present at the level of olfactory axons but the resolution of light-microscope in situ hybridization did not permit the axons to be distinguished from the closely apposed ensheathing cells. In this study, the localization of CGRP mRNA was studied at early developmental stages (E13–15) through in situ hybridization at the transmission electron-microscope (TEM) level. CGRP transcripts were observed exclusively in axons and not in ensheathing cells. The distribution of transcripts in the axons suggests that they are associated with intermediate filaments rather than microtubules. In addition, a careful ultrastructural analysis provided evidence that polysomes and membrane-bound ribosomes are present in such axons, suggesting that the peptide could be synthesized locally.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051158
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Prenatal development of the serotonin transporter in mouse brain (1997)
    Springer
    Cell & tissue research 289 (1997), S. 211-221 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Serotonin ; Transporter ; [3H]citalopram ; Autoradiography ; Brain ; Development ; Mouse (NMRI)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The prenatal development of the serotonin transporter was analyzed in mouse brain and spinal cord by autoradiographic localization of [3H]citalopram binding. Transporter expression started at embryonic day (E) 12 in two discontinuous bands in the anterior and posterior brainstem. Labeling extended cranially and caudally, reaching the basal diencephalon at E 13, the septal complex at E 15, and the cerebral cortex at E 16. The caudal extension of the labeling descended at the ventrolateral margin of the spinal cord and reached lumbar levels at E 14. At E 17–E 18, [3H]citalopram binding emerged in the striatum, amygdaloid area, ventrobasal thalamus, paraventricular and periventricular hypothalamic nuclei, and substantia nigra. The overall spatiotemporal expression pattern of the serotonin transporter in the mouse agrees with data on the immunohistochemical localization of serotonin in the rat embryo. These results suggest that serotonergic fibers have the equipment to engage in transmitter reuptake long before synapse formation, and that transporter expression might represent a prerequesite for the developmental functions exerted by serotonin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050868
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Cell surface changes during mitosis and cytokinesis of epithelial cells (1984)
    Springer
    Cell & tissue research 237 (1984), S. 409-417 
    Details
    ISSN: 1432-0878
    Keywords: Mitosis ; Cytokinesis ; Microvilli ; Scanning electron microscopy ; Cell surface
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary PtK2 cells were studied with scanning electron microscopy to record changes on the cell surface during mitosis and cytokinesis. During prophase, prometaphase and metaphase, the cells remain very flat with few microvilli on their surfaces. In anaphase cells, there is a marked increase in the number of microvilli, most of which are clumped over the separating chromosomes and polar regions of the mitotic spindle leaving the surface of the interzonal spindle region relatively smooth. Microvilli appear over the interzonal spindle region in telophase and the cells also increase in height. At the beginning of cleavage, the distribution of microvilli is roughly uniform over the surface but it becomes asymmetric at the completion of cleav-age when the daughter cells begin to spread. At this time most microvilli are over the daughter nuclei and the surfaces that border the former cleavage furrow. The regions of the daughter cells distal to the furrow are the first to spread and their surfaces have very few microvilli. When chromosome movement is inhibited by either Nocodazole or Taxol, microvilli formation is inhibited on the arrested cells. Nevertheless cell rounding still takes place in the normal time period. It is concluded from these observations that the signal for the onset of chromosome movement in anaphase is accompanied by a signal for the formation of microvilli. It is suggested that there is also a separate signal for the cell-rounding event in mitosis and that microvilli do not play a role in this contractile process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228425
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Scanning electron microscopy of the renal corpuscle of the mesonephros in the lamprey, entosphenus japonicus martens (1978)
    Springer
    Cell & tissue research 187 (1978), S. 105-113 
    Details
    ISSN: 1432-0878
    Keywords: Mesonephros ; Lamprey ; Renal corpuscle ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The renal corpuscle of the lamprey mesonephros was studied under the scanning electron microscope. Bowman's capsules with individual spaces are chockshaped sacs closely packed together along a medial artery. The lateral walls of the capsules are apposed to those of neighbouring capsules. Glomerular capillaries from the medial artery extend radially between the apposed walls of neighbouring Bowman's capsules. Bulgings of capillaries into the capsular space are associated with mesangial folds of the capsular epithelium. The transitional zone of the visceral layer with podocytes and the parietal layer of squamous epithelium is bounded by linearly arranged rod-shaped epithelial cells. Apertures of the urinary tubule are lined by cells equipped with a fascicle of cilia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220622
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Cytochalasin B and water transport (1978)
    Springer
    Cell & tissue research 188 (1978), S. 375-388 
    Details
    ISSN: 1432-0878
    Keywords: Urinary bladder ; Skin ; Toad, frog ; Water flow ; Na transport ; Vasopressin ; Cytochalasin B ; Microfilaments ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A morpho-functional study of the effects of cytochalasin B (CB) on Na and water transport was made in amphibian epithelia. The functional studies confirmed the dissociation of the natriferic and hydrosmotic effects of vasopressin in toad urinary bladders exposed to CB and showed in addition that the block of the hydrosmotic effect was reversible and could still be induced in epithelia maximally stimulated with the hormone. Scanning electron microscopy revealed that CB, per se, did not alter the apical surface of the bladders. An almost total loss of microvilli of granular cells was seen, however, if CB was associated with vasopressin and an osmotic gradient. The results suggest two points: a) the block of the hydrosmotic flow induced by CB is due to factors beyond the apical membrane; b) microfilaments may be important mechanochemical transducers in the chain of events leading to the hydrosmotic effect of vasopressin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219779
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Differentiation of ovarian and testicular interstitial cells during embryonic and post-embryonic development in mice (1978)
    Springer
    Cell & tissue research 188 (1978), S. 465-480 
    Details
    ISSN: 1432-0878
    Keywords: Steroidogenic cells ; Gonads ; Mouse ; Development ; Ultrastructural differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Different steps in mouse ovarian and testicular development have been studied in order to compare the time sequences during the in vivo differentiation of steroidogenic cell populations growing in contact with male and female gonocytes. These time sequences indicated a basic common developmental pattern: early signs of steroid synthesis in the male gonad, but late entering into meiotic prophase of XY germ cells; early meiosis but late steroidogenic activity in the ovary. In both male and female interstitial tissues, signs of involution were found following a period of exponential development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219784
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Quantitative observations of the effect of sex-steroids on the postnatal development of LH-cells (1978)
    Springer
    Cell & tissue research 188 (1978), S. 491-496 
    Details
    ISSN: 1432-0878
    Keywords: Castration ; LH-cells ; Rat ; Development ; Sex-steroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of sex-steroids on the LH-cell development in neonatal rats were studied. The cells were stained immunohistochemically by applying anti-HCG serum. On the second day after birth some of the animals of both sexes were gonadectomized and simultaneously injected with testosterone or estradiol (50 or 200 μg). The remaining animals were either gonadectomized or injected with either one of the sex-steroids. The LH-cell numbers in each group were determined on the 12th day of age from serially cut histological sections of the pituitary. In castrated males the number of LH-cells was about twice that of the intact animals. In the so-called sex-zone, LH-cells tended to be hypertrophied in castrates. These alterations in the appearance of LH-cells did not occur after ovariectomy. In gonadectomized animals injected with sexsteroids (200 μg), the cells were markedly reduced in number and size, both in males and females. Testosterone injection (50 μg) into intact newborn animals also suppressed the numerical development of LH-cells, especially in females. These alterations were particularly evident in the sex-zone in both sexes. Thus the present findings show that sex-steroids may be involved in sexual differences in morphological development of LH-cells in newborn rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219786
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    A scanning electron microscope study of myoepithelial cells in exocrine glands (1980)
    Springer
    Cell & tissue research 209 (1980), S. 1-10 
    Details
    ISSN: 1432-0878
    Keywords: Myoepithelial cell ; Exocrine gland ; Scanning electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By removing connective tissue components with enzymatic digestion followed by HCl-hydrolysis, myoepithelial cells (MECs) of the terminal portion in a variety of exocrine glands of the rat were examined with the scanning electron microscope. The profile of MECs varied considerably from gland to gland; MECs in the lactating mammary gland have a few long cytoplasmic processes in close contact with those of adjacent cells forming a continuous network around the terminal portion. Those of the exorbital lacrimal gland are stellate with many thin radiating processes with tapered ends that terminate freely. MECs in the sublingual gland are characterized by a number of broad and extensive cellular processes. MECs in the submandibular gland are similar in appearance to those of the exorbital lacrimal gland, but with more extensive cellular processes that form a more or less continuous network with those of the adjacent cells. No MECs were observed on the terminal portion of the parotid gland where the cells appear to be lodged on the intercalated duct. The relative surface area covered by MECs per terminal portion was also found to vary significantly, being 24% in the lactating mammary, 17% in the exorbital lacrimal, 48% in the sublingual, and 25% in the submandibular glands. The findings are discussed in relation to the physical properties of secretions in different glands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219918
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    The occluding junctions of mouse duodenal enterocytes during development (1981)
    Springer
    Cell & tissue research 217 (1981), S. 65-77 
    Details
    ISSN: 1432-0878
    Keywords: Freeze-fracture ; Occluding junctions ; Enterocytes ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The architecture of occluding junctions during the differentiation of the mouse duodenum was studied in freeze-fractured material. Irregular zonulae occludentes (ZO) (Type I) are numerous during fetal life, and are characterized by their irregular width, and by the presence of basal open-ended extensions fused with the discontinuous basal strand of the ZO. Regular ZOs (Type II), typical of the adult villous epithelium, appear after Type I junctions by day 16 of gestation. Two patterns are distinguishable: in the first, parallel strands of ridges and furrows are found without crossing branches; in the second pattern, the junction zone is organized like a network of short branches forming various types of polygons. In fetal and adult mice fasciae occludentes (FO) (Type III) are present on the lateral cell membranes; in unfixed specimens particles are found in the furrows of the E-face and pits on the ridges of the P-face. In fixed tissues, the particles are aligned on the ridges of the P-face. These results indicate that fixation with glutaraldehyde modifies considerably the affinity of junctional particles toward the P-face during the fracture process. Moreover, the presence of numerous large FOs on the lateral cell membranes of enterocytes during late fetal life and in the adult, is possibly related to cell movement along the intestinal villi.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233827
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Growth characteristics of ganglion cell axons in the developing and regenerating retino-tectal projection of the rat (1997)
    Springer
    Cell & tissue research 290 (1997), S. 395-403 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Axonal guidance ; Guidance molecules ; Development ; Regeneration ; Astrocytes ; Retino-tectal system ; Microglia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract.  Retinal ganglion cell (RGC) axons from the temporal retina project to the anterior superior colliculus (SC), whereas nasal retinal axons project to the posterior SC. The stripe assay has shown that temporal retinal axons avoid growing on membrane stripes from the posterior SC but nasal retinal axons show no growth preference. Several putative guidance molecules have been identified in target tissues for these axons during development in vertebrates. Regenerating axons from adult rat retinae also possess the capacity to recognize appropriate target cells and to form functional connections in vivo and in vitro. However, the expression of information for axonal guidance and target recognition in mammals and birds seems to be limited to the period when central nervous system projections develop during embryogenesis. Nevertheless, the deafferented adult rat SC re-establishes target information recognizable by embryonic rat retinae, although the re-expression of guidance factors after deafferentation does not seem to be a mere recapitulation of their normal developmental expression pattern. The roles of astrocytes and microglia in axon guidance are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050946
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Transthyretin distribution in the developing choroid plexus of the South American opossum (Monodelphis domestica) (1997)
    Springer
    Cell & tissue research 287 (1997), S. 621-624 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Transthyretin ; Albumin ; Immunohistochemistry ; Development ; Choroid plexus ; Opossum ; Monodelphis domestica (Marsupialia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The distributions of transthyretin and albumin in the choroid plexus during brain development have been compared. The South American opossum was chosen because the young are born around the time of choroid plexus formation. Previous work showed that in the adult opossum, transthyretin is expressed in the choroid plexus cells. However, systematic studies of transthyretin in the choroid plexus during development have not been carried out before. Transthyretin was present in 90–95% of the choroidal cells from birth to adulthood. In most cells, transthyretin immunoreactivity was concentrated in the apical region of the cytoplasm. Double labelling of choroid plexus sections with antibodies to albumin and transthyretin showed that 1–2% of cells were positive for both proteins. These findings suggest that from the very earliest stage of choroid plexus formation most epithelial cells both synthesize and contain transthyretin, and a few of these transthyretin-synthesizing cells also contain albumin that is probably being transferred from blood to the cerebrospinal fluid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050785
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    NADPH-diaphorase activity in the nervous system of the embryonic and juvenile pond snail, Lymnaea stagnalis (1998)
    Springer
    Cell & tissue research 292 (1998), S. 579-586 
    Details
    ISSN: 1432-0878
    Keywords: Key words NADPH-diaphorase ; Nitric oxide synthase ; Development ; ontogenetic ; Lymnaea stagnalis (Mollusca)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Nicotinamide-adenine-dinucleotide-phosphate-diaphorase (NADPH-d) histochemistry has been applied in the present study to determine the distribution of putative nitric oxide (nitric oxide synthase)-producing cells during embryonic and early postembryonic development in the pond snail, Lymnaea stagnalis L., with special reference to the nervous system. The first NADPH-d-positive structures appear as early as 18% of development (E18, trochophore stage) and correspond to the pair of protonephridia. These structures later show disintegration, although after metamorphosis (E26=75%) staining of their individually spreading cells can be observed until hatching. Peripheral sensory neurons in the foot, mantle edge and lips, and their afferents projecting to the central nervous system reveal NADPH-d activity in the postmetamorphosis period (E25–E27=E60%–E80%) of embryogenesis. After hatching (P1–P3), a number of stained sensory cells appear in the pharynx and esophagus. Some NADPH-d positive neuronal perikarya occur in the pedal and pleural ganglia, and a few weakly stained cells in the cerebral and buccal ganglia of juvenile snails. At the same time, a continuous bundle of reactive fibers is formed in the neuropil both through and through around the circumesophageal ganglion ring. The localization of NADPH-d activity in the developing nervous system of Lymnaea suggests that nitric oxide participates mainly in sensory processes. However, its role in specific intraganglionic integrative events cannot be excluded following embryonic metamorphosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051087
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Muscarinic and nicotinic receptor-mediated Ca2+ dynamics in rat adrenal chromaffin cells during development (1998)
    Springer
    Cell & tissue research 294 (1998), S. 109-123 
    Details
    ISSN: 1432-0878
    Keywords: Key words Muscarinic receptors ; Nicotinic receptors ; Adrenal chromaffin cells ; Ca2+ dynamics ; Development ; Catecholamines ; Exocytosis ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  To clarify when the cholinergic receptor-mediated secretion mechanism of developing adrenal chromaffin cells is expressed and becomes functional, morphological changes and intracellular calcium dynamics were studied by immunohistochemistry, electron microscopy, and Fura-2 digital image analysis. From embryonic day 14 to 16, adrenal medullary cells were immunoreactive to noradrenaline-synthesizing enzyme (dopamine β-hydroxylase) but not to adrenaline-synthesizing enzyme (phenylethanolamine N-methyltransferase). These cells contained either no granules or just a few granules of high electron density. Exocytotic figures were rarely observed in cells of the control or in cells after carbamylcholine stimulation. Nerve fibers in the adrenal medulla contained either no clear vesicles or very few. Neither methacholine nor nicotine caused a change of intracellular Ca2+ in most chromaffin cells. From embryonic day 18 to 20, chromaffin cells were immunoreactive to both dopamine β-hydroxylase and phenylethanolamine N-methyltransferase and they contained relatively numerous secretory granules. Exocytotic figures were often seen in cells after carbamylcholine stimulation. The intra-adrenal nerve fibers contained numerous clear vesicles and a few dense-cored vesicles. Methacholine caused no rise of intracellular Ca2+, but nicotine induced a low to relatively high rise in many cells. From postnatal day 2 or 3 to postnatal week 1, numerous cells were immunoreactive to both dopamine β-hydroxylase and phenylethanolamine N-methyltransferase, whereas some cells were reactive to dopamine β-hydroxylase alone. Chromaffin cells were divisible into noradrenaline cells and adrenaline cells based on the ultrastructural features of their granules. Methacholine induced a moderate rise of intracellular Ca2+ and nicotine caused a high rise in many chromaffin cells, whereas, in some chromaffin cells, methacholine induced no rise of intracellular Ca2+ and nicotine induced a high rise. These results suggest that morphological changes of the developing cells and the intra-adrenal nerve fibers are related to the expression of a cholinergic receptor-mediated secretion mechanism and that this mechanism via a nicotinic receptor-mediated Ca2+ signaling pathway precedes the muscarinic receptor-mediated one during development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051161
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Fine structure and distribution of antennal sensilla of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae) (1998)
    Springer
    Cell & tissue research 291 (1998), S. 525-536 
    Details
    ISSN: 1432-0878
    Keywords: Key words Olfaction ; Chemoreceptors ; Aggregation pheromone ; Scanning electron microscopy ; Transmission microscopy ; Antennae ; Schistocerca gregaria (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The fine structure and distribution of various types of antennal sensilla in three nymphal stages and in adults of both solitary-reared (solitary) and crowd-reared (gregarious) phases of the desert locust, Schistocerca gregaria, were investigated by scanning and transmission electron microscopy. Four types of sensilla were identified: sensilla basiconica, s. trichodea, s. coeloconica and s. chaetica. S. basiconica contain up to 50 sensory neurons, each of which displays massive dendritic branching. The sensillar wall is penetrated by a large number of pores. In contrast, s. trichodea contain one to three sensory neurons that branch to give five or six dendrites in the sensillar lumen; the sensillum wall is penetrated by relatively few pores. The s. coeloconica are situated in spherical cuticular pits on the antennal surface. The s. coeloconica are of two types: one type contains one to three sensory neurons with double sensillar walls penetrated by slit-like pores, whereas the second type contains four sensory neurons with non-porous double sensillar walls. The s. chaetica have a flexible socket and a thick non-porous sensillum wall and contain four sensory neurons that send unbranched dendrites to a terminal pore. A fifth sensory neuron of the s. chaetica terminates in a tubular body at the base of the hair. S. basiconica and coeloconica are normally distributed over the entire antennal flagellum, with a concentration in the middle segments; s. trichodea have three areas of concentration on the 5th, 10th and 14th flagellar segments. Sensilla chaetica are most abundant on the terminal segment. Locusts raised in solitary conditions have more olfactory sensilla (s. basiconica and s. coeloconica) than crowd-reared locusts. The difference in sensillar numbers is more evident in adults than in nymphs. These results suggest that differences in the odour-mediated behaviour of nymphs and adults, and between the phases of S. gregaria, may be attributable to differences at the sensory input level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051022
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Scanning electron microscopy of stromal cells of human placental villi throughout pregnancy (1984)
    Springer
    Cell & tissue research 235 (1984), S. 647-655 
    Details
    ISSN: 1432-0878
    Keywords: Classification of chorionic villi ; Fixed stromal cells ; Macrophages ; Placenta (human) ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphological changes in fixed stromal cells and Hofbauer cells were studied throughout pregnancy in different types of placental chorionic villi by scanning electron microscopy. In the mesenchymal villus the fixed stromal cells were characterized by thin cytoplasmic processes. Hofbauer cells exhibited blebs on their surface. Large sail-like processes with a crescent profile which surrounded well developed stromal channels and a small cell body typified the small reticulum cells of the immature intermediate villus. The Hofbauer cells here displayed blebs, microplicae and large lamellipodia. Short cytoplasmic expansions and a large cell body characterized the fibroblasts present inside the stem villus. Hofbauer cells were rare, having blebs or a few short lamellipodia. The mature intermediate villus contained small and large reticulum cells. The latter had a much larger cell body than the small ones and displayed a few short cytoplasmic processes partly delimiting narrow incomplete stromal channels. Occasional Hofbauer cells with small microplicae and/or blebs were present. The small reticulum cells and fibroblasts present in the terminal villus showed similar morphological features as above. However, the former exhibited less developed cytoplasmic extensions and therefore no stromal channels were observed. In the terminal villus, the morphology of the rare Hofbauer cells was similar to that found in the mature intermediate villus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226964
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    On the development of midpiece mitochondria of mouse spermatozoa (1979)
    Springer
    Cell & tissue research 199 (1979), S. 349-352 
    Details
    ISSN: 1432-0878
    Keywords: Spermatozoa ; Mitochondria ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary As seen by scanning electron microscopy, the mitochondrial helix in the developing midpiece of mouse testicular spermatozoa is dextral in direction and consists of spherical mitochondrial units arranged in an orderly array of four units per gyre: three appearing in face view and a fourth hidden from view at the back of the gyre. As the spermatozoa mature, the dextral helix is transformed into a sinistral helix. Its constituent spherical mitochondria either change direction abruptly without changing shape; or having first become semilunar or diamond-shaped, they change direction gradually. Mitochondrial division follows the change in helical pitch producing a double sinistral helix. The spherical (or semilunar/diamond-shaped) mitochondria presumably elongate to form the units of the mature midpiece.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236144
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Proliferation and differentiation of intestinal epithelial cells during development of Barbus conchonius (Teleostei, Cyprinidae) (1984)
    Springer
    Cell & tissue research 236 (1984), S. 207-216 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Enterocytes ; Fish ; Mitosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The processes of proliferation, cell division and differentiation of intestinal epithelial cells have been studied during development of the fish, Barbus conchonius. On the 3rd day, nearly all cells of the presumptive gut proliferate. Once the intestinal epithelium begins to differentiate, a decreasing percentage of proliferative cells can be found. On the 7th day, when intestinal folds start to develop, the proliferative cells become restricted to the future basal parts of the folds. Ultrastructural examination of 3H-thymidine-labeled cells and mitotic cells of 6-day-old larvae shows that functional enterocytes are proliferative. The same feature is suggested for older fish. Proliferating undifferentiated “dark” cells, characterized by many free ribosomes and a few organelles, are also present in the intestinal epithelium of larval fish; they are considered to be stem cells, mainly for goblet cells. Proliferating goblet cells and enteroendocrine cells were not observed. The latter cell type is scarce and has a long turnover time. A common feature of all these dividing cells is the presence of isolated spherical to cylindrical lamellar structures which may have lost contact with the cell membrane during prophase; they probably regain this contact by fusion with the cell membrane at the end of mitosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216533
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Effects of colchicine and cytochalasin B on hypertonicity-induced changes in toad urinary bladder (1984)
    Springer
    Cell & tissue research 236 (1984), S. 585-591 
    Details
    ISSN: 1432-0878
    Keywords: Urinary bladder, toad ; Scanning electron microscopy ; Hypertonicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Coincident with an increase in the water permeability of toad urinary bladder induced by serosal hypertonicity, a transformation of the ridge-like surface structures of the granular cells into individual microvillous structures occurs. This study was initiated to establish whether the transformation is mediated by the cytoskeletal network and, thus, can be prevented by disruption of microtubulemicrofilament function with colchicine or cytochalasin B (CB). Scanning electron microscopy revealed the characteristic branching ridges on granular cells of control bladder incubated with colchicine or CB. In contrast, transformation of ridges to discrete microvilli was observed in experimental bladders exposed to serosal hypertonicity alone or in combination with either colchicine or CB. These results suggest that the mechanism underlying hypertonicity-induced surface changes which are associated with increased water permeability does not involve either microtubules or microfilaments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217226
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Scanning electron-microscopic study of Reissner's fiber in the caudal spinal cord of the cat and rabbit (1984)
    Springer
    Cell & tissue research 237 (1984), S. 181-183 
    Details
    ISSN: 1432-0878
    Keywords: Reissner's fiber ; Scanning electron microscopy ; Spinal cord ; Cat ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The caudal portion of Reissner's fiber was examined by scanning electron microscopy (SEM) in the spinal cord of the cat and rabbit. In some preparations of both species the fiber displayed in the sinus terminalis of the central canal either stump-like terminations or structural modifications such as knot-like swellings and convolutions. In the same area homogeneous material could also be found, which obviously originated from the disintegrating fiber.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229214
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Scanning electron microscopic study of the freeze-fractured pineal body of the rat (1979)
    Springer
    Cell & tissue research 201 (1979), S. 129-135 
    Details
    ISSN: 1432-0878
    Keywords: Pineal body ; Freeze-fracturing ; Scanning electron microscopy ; Wistar rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The three-dimensional ultrastructure of the pineal body of the rat is described on the basis of freeze-fractured preparations. The pineal capsule consists of irregular cells with very flat and perforated processes. Through these openings, extremely branched canaliculi, extending to almost every pineal cell, communicate with the tissue compartment outside the organ. The pericapillary spaces contain, in juxtaposition with capillaries of the fenestrated type, nerve fibers as well as a flocculent granular and filamentous material of unknown origin and chemical nature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238052
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Immunohistochemical study of S-100 protein in the postnatal development of Müller cells and astrocytes in the rat retina (1984)
    Springer
    Cell & tissue research 238 (1984), S. 503-508 
    Details
    ISSN: 1432-0878
    Keywords: S-100 ; Müller cell ; Astrocyte ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rat retina was studied by immunohistochemistry with antibody to S-100 protein during the first three postnatal weeks. Immunoreactive astrocytes are first detected subjacent to the inner limiting membrane close to the optic disc. They gradually increase in number and spread toward the ora serrata along the inner surface of the retina as the development proceeds. S-100-immunostained Müller cells are first identified on the 12th postnatal day although their immunoreactivity is much weaker than that of astrocytes at the same stage. This differential intensity of the immunoreactivity of the two cell types facilitates observation of the entire shape of the astrocyte. This characteristic reveals that cellular investments of blood vessels in the inner retina are formed by astrocytic processes whereas those in the outer plexiform layer are derived from processes of Müller cells. The cellular investment becomes complete by the 18th postnatal day.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219865
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Morphological studies of different mitochondrial populations in monkey myocardial cells (1984)
    Springer
    Cell & tissue research 238 (1984), S. 577-582 
    Details
    ISSN: 1432-0878
    Keywords: Mitochondria ; Heart ; Scanning electron microscopy ; Thin sections ; Freeze-fracturing ; Macaca fuscata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of mitochondria in monkey myocardial cells was investigated by scanning electron microscopy, thin sections and freeze-fracturing. Mitochondria with well-developed cristae were distributed around the nucleus, between the myofibrils and beneath the sarcolemma. Those clustered near the the poles of the nucleus were generally spherical in shape. Interfibrillar mitochondia were arranged in longitudinal rows between the myofibrils, were elongated and usually about the same length as a sarcomere. Subsarcolemmal mitochondria varied in size and shape, being rod-like, spherical, polygonal or horseshoe-like. There were usually two profiles of subsarcolemmal mitochondria in each section of sarcomere, although sometimes one or three occurred, and they were typically oriented perpendicularly to the myofibrils. These morphological differences among mitochondria could reflect functional and/or mechanical properties in the various cellular locations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219874
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    A Golgi-electron-microscopical study of the structure and development of the lamina ganglionaris of the locust optic lobe (1981)
    Springer
    Cell & tissue research 216 (1981), S. 377-401 
    Details
    ISSN: 1432-0878
    Keywords: Lamina ganglionaris ; Locust ; Neurons ; Development ; Light and electron microscopy ; Golgi study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The gross structure as well as the neuronal and non-neuronal components of the lamina ganglionaris of the locust Schistocerca gregaria are described on the basis of light- and electron-microscopical preparations of Golgj (selective silver) and ordinary histological preparations. The array of optic cartridges within the lamina neuropile — their order and arrangement — and the composition of the cartridges are described. There are six types of monopolar neurons: three whose branches reach to other cartridges and three whose branches are confined to their own cartridges. Retinula axons terminate either in the lamina or the medulla neuropiles. There are three types of centrifugal neurons, two types of horizontal neuron, as well as glia and trachea in the lamina neuropile. The development of the lamina neuropile is described in terms of developing monopolar and centrifugal axons, growing retinula fibres, and composition of the developing optic cartridges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233626
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Role of innervation on the embryonic development of skeletal muscle (1980)
    Springer
    Cell & tissue research 210 (1980), S. 383-393 
    Details
    ISSN: 1432-0878
    Keywords: Avian skeletal muscle ; Development ; Normal, aneural, paralyzed muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The extent to which the motor innervation regulates the embryonic development of skeletal muscle was investigated by comparing changes in normal, aneural, and paralyzed superior oblique muscle of the duck embryo. The muscle was made aneural by permanently destroying the trochlear motor neurons with electrocautery on day 7 i.e., three days prior to innervation. Embryos were paralyzed by daily application of α-bungarotoxin onto the chorioallantoic membrane from day 10 onwards. The differentiation of myoblasts and myotubes in the aneural muscle was severely affected and did not progress to the myofiber stage. A mass of dead cells in the aneural muscle was replaced by connective tissue. Although the differentiation of myoblasts and myotubes was also retarded in the paralyzed muscle, numerous muscle cells progressed to the myofiber stage. Neuromuscular junctions of normal ultrastructure were seen in all paralyzed muscles. Degeneration of some cells in the paralyzed muscle occurred but there was no evidence of a massive wave of cell death similar to that observed in the aneural muscle. These observations suggest that both the trophic factors from the nerve and the nerve-evoked muscle activity are essential for the execution of the developmental program of the muscle. Trophic factors may play a larger role in differentiation, and maintenance of the muscle than muscle activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220196
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Studies on formation and resorption of fish scales (1980)
    Springer
    Cell & tissue research 211 (1980), S. 303-316 
    Details
    ISSN: 1432-0878
    Keywords: Fish scale ; Fine structure ; Development ; Calcification ; Cyprinodon variegatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Scale formation in Cyprinodon variegatus was found to be initiated at about 26 to 30 days after hatching. Ultrastructural investigation revealed that within 4 to 6 h in the first-formed scales the marginal cells begin to flatten and differentiate into osteogenic cells, which later change to osteoblasts and fibroblasts. These cells are separated from the surrounding epithelial cells by a basal lamina. The osteoid is formed by the marginal and osteogenic cells; the osseous layer by the osteoblasts; and the fibrillary plate by the fibroblasts. The osteoid is formed within 2 to 3 h after the initiation of the scale, and within 20 to 24 h the osseous layer is formed. Hydroxyapatite crystals are deposited in the matrix of the osseous layer without apparent association with collagen fibers. No matrix vesicles or dense bodies are evident at the sites of calcification. The fibrillary plate arises 18 to 20 h after the initiation of the scale. It is also partially calcified, but not before the third week of scale formation. The crystals develop almost exclusively between the collagen fibers at the extreme edge of the calcifying front, but solid calcification of the fibers results with further growth of the crystals. The fibroblasts appear to participate in calcification of the fibrillary plate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236451
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    The parcellation theory and its relation to interspecific variability in brain organization, evolutionary and ontogenetic development, and neuronal plasticity (1980)
    Springer
    Cell & tissue research 213 (1980), S. 179-212 
    Details
    ISSN: 1432-0878
    Keywords: Neocortex ; Evolution ; Development ; Plasticity ; Visual system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Recently discovered neocortical equivalents in anamniotes and certain patterns of interspecific variability in brain organization provide new insights into evolutionary and ontogenetic mechanisms of development. The new data suggest that nervous systems become more complex, not by one system invading another, but by a process of parcellation that involves the selective loss of connections of the newly formed daughter aggregates and subsystems. The parcellation process is reflected in the normal ontogenetic development of the CNS in a given species and can be manipulated, to a certain extent, by deprivation or surgically induced sprouting. The parcellation theory allows certain predictions about the range of variation of a given system at all levels of analysis including the cellular and aggregate levels. For example, the interspecific variability in organization of cortical columns, thalamic nuclei, cortical areas and tectal layers can be explained. The findings, summarized here, suggest that diffuse, undifferentiated systems existed in the beginning of vertebrate evolution and that during the evolution of complex behaviors, and analytical capacities related to these behaviors, a range of patterns of neural systems evolved that relate to these functions. One principle underlying the growth, differentiation and multiplication of neural systems appears to be the process of parcellation as defined by the theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234781
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Surface morphology of rat peritoneal mast cells during in vitro regeneration after histamine secretion (1981)
    Springer
    Cell & tissue research 216 (1981), S. 647-654 
    Details
    ISSN: 1432-0878
    Keywords: Mast cells ; Regeneration ; Exocytosis ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cell-surface morphology of regenerating mast cells was followed over a period of 48 h after histamine release. Control cells (not stimulated to secrete) were characterized by anastomosing folds of membrane of equal depth and width. During exocytosis these folds disappeared and were replaced by deep cup-shaped flaps of membrane evident in cells incubated for 10 min. During the first hours of regeneration these flaps fused mutually or with the plasma membrane. This activity suggests membrane retrieval, maybe specifically recycling the granule-type patches of membrane. Membrane-fusion activity was observed to some degree also after extended incubation. After 48 h of incubation the regeneration process was still not completed, as indicated by the fact that holes leading to intracellular cavities could still be found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238659
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Catecholamine-storing cells in the adrenal medulla of the pre- and postnatal rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 155-170 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal medulla ; Development ; Acetylcholinesterase ; Small granule cells ; Ultramorphology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the rat adrenal medulla was studied at the ultrastructural level with particular emphasis placed on early discrimination of different catecholamine-storing cells. The first granule-containing cells, phaeochromoblasts, were seen at day 15 of gestation migrating into the anlage of the cortex. These cells were characterized by a few small granules (80–120 nm in diameter) and a high nuclear to cytoplasmic ratio. Presumably due to differentiation into chromaffin cells, they were no longer present after the eighth postnatal day. Maturation of phaeochromoblasts was indicated by an increase in number and size of their storage granules and a decrease in the nuclear to cytoplasmic ratio. Noradrenaline and adrenaline cell types were first clearly discernible at day 21 of gestation. Another cell type, a giant cell, was also recognized at this stage. In the adult animal, noradrenaline, two morphologically different types of adrenaline, and small granule-containing cells were observed. By applying acetylcholinesterase histochemistry, it was found that at day 17 of gestation a small population of granule-storing cells showed strong positive staining in the endoplasmic reticulum. In the adult animal this cell type was further characterized by small-storage granules. Other chromaffin cells began to show weak staining within the endoplasmic reticulum at day 19 of gestation. This staining appeared more frequently within adrenaline than noradrenaline cells. However, even in the adult animal many cells of both types were completely negative. It is concluded that acetylcholinesterase histochemistry is a useful method for early discrimination of small granule-containing cells in the developing rat adrenal medulla.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233834
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Simultaneous apocrine and merocrine secretion in the rat coagulating gland (1999)
    Springer
    Cell & tissue research 295 (1999), S. 495-504 
    Details
    ISSN: 1432-0878
    Keywords: Key words Coagulating gland ; Apocrine secretion ; Merocrine secretion ; Immunocytochemistry ; Immunoelectron microscopy ; Scanning electron microscopy ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The coagulating gland of the rat synthesizes two prevalent secretory proteins (transglutaminase and 115 K) that are discharched in a different manner, one being secreted in an apocrine fashion (transglutaminase) and the other one in a merocrine way (115 K). Differences in the intra- cellular pathway and the release of either protein were studied using immunofluorescence on semithin sections, immunoelectron microscopy of preembedding-processed chopper sections and postembedding-processed ultrathin sections of rat coagulating gland. Immunohistochemical staining using an anti-transglutaminase antibody resulted in dense labeling of the cytoplasm of secretory cells and their apical blebs, whereas the cisternae of the rough endoplasmic reticulum and the Golgi apparatus were completely unlabeled. When, on the contrary, the anti-115 K antiserum was used, dense labeling of the cisternae of the rough endoplasmic reticulum, the Golgi apparatus, and the secretory granules was seen. Intraluminal secretion was also labeled, but the secretory blebs remained unlabeled. Our findings show that, in the coagulating gland of the male rat, the two secretory proteins studied are processed in parallel, but at completely different intracellular pathways. They are released via different extrusion mechanisms. Transglutaminase is synthesized outside the endoplasmic reticulum, reaches the apical cell pole by free flow in the cytoplasm, and is released via apocrine blebs, the membranes of which appear to be derived from the apical plasma membrane. The protein 115 K, on the other hand, follows the classic route, being synthesized within the cisternae of rough endoplasmic reticulum, subsequently glycosylated in the Golgi apparatus, and released in a merocrine fashion. The mutual exclusion of the two secretory pathways and the regulation of the alternative release mechanism are still unresolved issues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051255
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Fibroblast growth factor-2 (FGF-2) and FGF-receptor (FGFR-1) immunoreactivity in embryonic spinal autonomic neurons (1997)
    Springer
    Cell & tissue research 287 (1997), S. 471-480 
    Details
    ISSN: 1432-0878
    Keywords: Key words: FGF-2 ; FGF receptor-1 ; Autonomic nervous system ; Sympathetic preganglionic neurons ; Spinal cord ; Development ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The development of the nervous system appears to be under the control of multiple growth factors, neurotrophins and cytokines, which may be expressed either continuously or transiently throughout defined stages of cellular generation, proliferation or differentiation. Fibroblast growth factor (FGF) cytokines and their receptors are abundantly expressed in the embryonic nervous system but their localization at autonomic levels in the fetal spinal cord has not yet been detailed. Immunoreactivity to FGF-2, probably the best characterized member of the FGF family (FGF-1 to FGF-10) and of one of its high affinity receptors, FGFR-1, was found in autonomic neurons at embryonic day E14, the peak day of generation and proliferation in the common ventral motoneuron pool. It was also continuously present throughout the investigated subsequent stages (E15 to postnatal day P30). Immunogold electron microscopy revealed the cytoplasmic localization of FGF-2 and FGFR-1 in intermediolateral neurons, the major group of sympathetic preganglionic neurons in the spinal cord. In these neurons, immunocytochemistry from E14 onwards showed the co-distribution of both markers at the period of axonal outgrowth to peripheral targets, e.g. the adrenal medulla. Our findings suggest autocrine and/or paracrine actions of FGF-2 for sympathetic preganglionic development but do not support its role as a target-derived neurotrophic factor for autonomic neuron development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050771
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    The angioarchitecture of estrous, pseudopregnant and pregnant rabbit ovary as seen by scanning electron microscopy of vascular corrosion casts (1997)
    Springer
    Cell & tissue research 288 (1997), S. 353-363 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Ovary ; Vascularization ; Vascular corrosion casts ; Scanning electron microscopy ; Countercurrent mechanism ; Rabbit (New Zealand white)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Ovarian angioarchitecture was studied by scanning electron microscopy of vascular corrosion casts in estrous, pseudopregnant (stimulated with human chorionic gonadotropin) and pregnant rabbits. In all samples, the proper ovarian branch of the ovarian artery (ramus ovaricus) entered the ovarian hilus near the caudal pole of the organ and ran parallel to the major axis of the hilus. The extraovarian venous drainage was formed by several vessels emptying into a distal large vein. The ramus ovaricus exhibited various degrees of coiling and branched in the medulla. The coiling of the ramus ovaricus and its ramifications were maintained in all samples. A venous meshwork and/or flat vein branches closely enveloped the arterial coils found in the hilus and outer medulla. At this level numerous arteriovenous contacts were demonstrated in all samples. The coiled arteries, prior to entering the ovarian cortex, supplied several small peripheral follicles which were drained by the hilar veins. In the cortex the coiled arteries branched in numerous thin, straight or slightly undulated arterioles which supplied developing estrous follicles and pseudopregnant corpora lutea. The arterioles supplying the pregnant corpora lutea were long, large and tightly spiraled. The venous drainage followed the modifications of the arterial supply. These data demonstrate that ovarian cycle and pregnancy induced significant changes in the cortical vessels, which adapted their structure to the temporary functional needs of the recruited follicles or corpora lutea. Hilar and medullary vessels have permanent structures that may represent morphological devices for (a) a continuous control of the blood flow (spiral arteries) and (b) a local recirculation of endocrine products (arteriovenous contacts) comparable to the ”countercurrent mechanism” previously shown to operate in ovaries of other species, but not yet found in rabbits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050821
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Morphogenesis and pattern formation in the retina of the crayfish Procambarus clarkii (1998)
    Springer
    Cell & tissue research 293 (1998), S. 535-550 
    Details
    ISSN: 1432-0878
    Keywords: Key words Crayfish ; Retina ; Development ; Morphogenesis ; Rhabdome ; Ommatidia ; Procambarus clarkii (Crustacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Pattern formation and ommatidial differentiation in the crayfish retina were analyzed using confocal, light and electron microscopy. Optic primordia first appear in the embryo as round elevations covered by a surface epithelial layer. Retinal differentiation begins with a wave of mitotic activity that moves across this epithelium from lateral to medial. Ommatidial cell clusters are visible at the surface along a transition zone, which lies at the interface of the medial undifferentiated retina and the lateral patterned retina. This zone is 8–10 cells wide and composed of small uniform cell profiles. Lateral to the transition zone the initial ommatidial cell clusters form staggered rows across the surface. Each first row cluster contains eight retinula cells surrounded by four cone, two corneagenous and two distal pigment cells. Ommatidial clusters in the first nine rows show significant changes in their organization, which are visible at the surface of the retina. In row 10 the retinula cells recede from the surface and the cone cells close in above them creating a constant cell pattern at the surface. Rhabdome development begins distally and extends downward as the retinula cluster recedes from the surface. Movement of the retinula cells inward and enlargement of the cone and corneagenous cells at the surface creates a two-tiered organization characteristic of each ommatidium. Comparison of retinal pattern formation and differentiation in the crayfish with retinal morphogenesis in Drosophila and other insects show several similarities between the two arthropod groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051146
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Regulation of topographic projection by the Eph family receptor Bsk (EphA5) and its ligands (1997)
    Springer
    Cell & tissue research 290 (1997), S. 251-259 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Topographic projection ; Eph family receptor Bsk ; Bsk ligands ; Gradients ; Development ; Hippocamposeptal system ; Olfactory and retinotectal systems ; Axonal guidance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract.  Topographic projection is a general feature of brain architecture and is critical for appropriate information processing and coding. Nevertheless, little is known about the mechanisms that govern topographic organization. The Eph family receptor tyrosine kinases and ligands have recently been implicated in the specification of topographic maps. We have shown that Bsk, an Eph family receptor, and its ligands are expressed in a complementary fashion in neurons and targets, respectively, in several neural systems. For example, in the hippocampus, Bsk is expressed in an increasing lateral to medial gradient. In contrast, at least three different ligands, viz., Elf-1, LERK3/Ehk1-L, and AL-1/RAGS/LERK7, are transcribed in complementary (opposing) gradients in the hippocampal subcortical target, the lateral septum. However, the spatial and temporal distribution of the ligands are different, such that combinatorially they specify the full target region during development. Consistent with a key role in hippocamposeptal topographic projection, the ligands selectively inhibit the growth of the topographically inappropriate medial hippocampal neurites but sustain the growth of the appropriate lateral neurites. Our studies indicate that the interaction of Bsk and its ligands restricts the receptor-positive medial neurons to the topographically appropriate, ligand-poor dorsal septal target. In addition to the hippocamposeptal system, Bsk and its ligands are also expressed in afferents and targets of several other systems, including the olfactory and the retinotectal systems. Consequently, Bsk and its ligands may play important roles in neuron-target interactions in multiple neural circuits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050929
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Developmental expression of galanin-like immunoreactivity by members of the avian sympathoadrenal cell lineage (1999)
    Springer
    Cell & tissue research 295 (1999), S. 33-41 
    Details
    ISSN: 1432-0878
    Keywords: Key words Neuropeptides ; Sympathetic ; Development ; Adrenal ; Chromaffin ; Neuron ; Galanin ; Chicken
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The developmental coexpression of galanin-like immunoreactivity with the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH) was studied in the avian embryo sympathoadrenal system using double-labeling immunocytochemistry. Galanin-like immunoreactivity is expressed by various catecholaminergic cell populations, namely sympathoblasts, chromaffin and small intensely fluorescent (SIF) cells, but not by principal neurons of the paravertebral sympathetic ganglia. Both galanin and somatostatin immunoreactivities are coexpressed in the adrenal and sympathetic ganglion primordia by the neural precursors, but the subsequent expression pattern of both peptides differs. Our results support the hypothesis that early sympathoblasts express a large repertoire of neuroactive substances and that the expression of these becomes restricted during further development as the sympathoblasts become principal neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051210
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Scanning electron microscopy of the wall of the third ventricle in the brain of Rana temporaria. Part IV. (1979)
    Springer
    Cell & tissue research 203 (1979), S. 53-64 
    Details
    ISSN: 1432-0878
    Keywords: Brain ; Third ventricle ; Rana temporaria ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The surface specializations of the wall of the third cerebral ventricle of Rana temporaria were investigated with the scanning electron microscope. These specializations can be divided into three types: cilia, large bulbous protrusions, and microvillus-like protrusions. Most parts of the ventricular surface are densely ciliated. In contrast, other regions are either scantily ciliated or devoid of cilia. Four areas of the ventricular surface are studded with numerous large bulbous protrusions. These large protrusions can be divided into two types: One type consists of intraventricular end bulbs of dendrites of secretory neurons. The other type is represented by large cytoplasmic extensions of ependymal cells. In the third ventricle of Rana, microvillus-like surface specializations of ependymal cells are ubiquitous structures. Generally, filiform protrusions of varying length are the predominant type. The microvillus-like specializations are transient structures, the number of which varies according to different physiological states of the ependymal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234328
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Microtubules, dendritic spines and spine apparatuses (1980)
    Springer
    Cell & tissue research 208 (1980), S. 171-181 
    Details
    ISSN: 1432-0878
    Keywords: Microtubules ; Dendritic spine apparatus ; Synapse ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using techniques for enhanced microtubular preservation, including albumin pretreatment (Gray, 1975), occipital cortex of rats was studied electron microscopically at various ages of development. A close structural relationship was seen between microtubules, sacs of SER and the postsynaptic “thickening” in primordial spines and with the dense “plate” material of spine apparatuses. Stereoscopic preparations in addition show a more complicated substructure than previously described for the “plate”. Microtubules may contribute to the formation of the “plate” of the spine apparatus which in turn is associated with the postsynaptic “thickening” of the mature spine. Possible functional correlates are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234868
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Postembryonic development of the antennal lobes in Periplaneta americana L. (1981)
    Springer
    Cell & tissue research 215 (1981), S. 563-575 
    Details
    ISSN: 1432-0878
    Keywords: Antennal lobes ; Development ; Sexual dimorphism ; Periplaneta americana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The postembryonic development of the antennal lobes of Periplaneta americana L. was examined with light- and electron-microscopical methods. There is no difference in the number of glomeruli and neurons in the antennal lobes of larval and adult animals. At hatching, the first larva already possesses the adult number of approximately 125 glomeruli and 500 to 560 deutocerebral neurons in the dorsolateral cell group of each antennal lobe. During postembryonic development the volume of the deutocerebral neurons increases three- to fourfold. The glomeruli of the first larva have about 7 % of the volume of the corresponding adult glomeruli. Since number, pattern, and size ratio of glomeruli (with the exception of the macroglomerulus) are constant in all larval stages and adult animals, it is possible to identify individual glomeruli. During the whole postembryonic development the ordinary glomeruli show a continuous volume increase, which parallels the increase in antennal sensory input. The macroglomerulus develops by way of special growth of two to four neuropil units, but not before the last three to four larval stages and only in males. Its growth precedes the formation of antennal pheromone receptors during the final molt; these receptors are known to project into the macroglomerulus. The development of the macroglomerulus in the last larval stages of the male may be caused by a genetically fixed growth program of specific deutocerebral neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233532
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Irido-corneal angle of mammalian eyes: Comparative morphology of encapsulated corpuscles in odontocete cetaceans (1980)
    Springer
    Cell & tissue research 210 (1980), S. 501-515 
    Details
    ISSN: 1432-0878
    Keywords: Mechanoreceptors ; Eye ; Dolphins ; Whales ; Irido-corned angle ; Light microscopy ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A study of the structure and distribution of encapsulated corpuscles (corpuscles of Rochon-Duvigneaud) in the irido-corneal (anterior chamber) angle in 42 adult eyes from nine species of odontocete cetaceans representing each of the five families in this group indicates a diversity of form and function. The corpuscles occur as single features or multiple groupings with each species having a distinct pattern. No definite phylogenic or environmental patterns were seen although sometimes there were similarities among related genera. The neural structure of the angle suggests that these receptors probably respond to a variety of stimuli including intraocular pressure, vitreous displacements, external muscular force applied to the sclera and cornea, and changes in the volume of the massive iris/choroid vascular system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220206
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Lack of Fc receptors on osteoclasts (1980)
    Springer
    Cell & tissue research 212 (1980), S. 509-516 
    Details
    ISSN: 1432-0878
    Keywords: Osteoclasts ; Macrophages ; Fc receptors ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fc and C3 receptors, which are characteristically present on macrophages, could not be demonstrated on osteoclasts maintained in situ on their normal substrates when assayed for by use of sheep red blood cells coated with immmoglobulin (Shapiro et al. 1979). The present study tested the hypotheses that Fc receptors are present only on the osteoclast surface adjacent to bone and that Fc receptors on osteoclasts can be uncovered by enzymes or stimulated to appear. Freeze-dried, inverted osteoclasts (and osteoblasts) obtained from the endocranium of newborn rats were tested for Fc receptors using the rosette assay and examined by scanning electron microscopy. No rosettes were observed on the surfaces of the osteoclasts that had been approximal to the bone. Bone specimens were cultured for 30 min at 37° C in control medium, or in medium with the addition of 10, 50 or 100 gmg/ml trypsin, 0.5 U/ml parathyroid extract (PTE), or 0.5 or 1U/ml parathyroid hormone 1–34 (PTH). Additionally, two week-old rats were injected intraperitoneally with PTE (1.5 U/g body weight or 1USP/g body weight) or with PTH (1U/g body weight) or with vehicle alone, 6 h before sacrifice. The specimens were assayed for Fc receptors and examined by scanning electron microscopy. Macrophages were always used as controls for the assay. No rosettes were present on osteoclasts subjected to any of these treatments. Accordingly, the hypotheses were not supported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236514
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Integrating bits and pieces: synapse structure and formation in Drosophila embryos (1999)
    Springer
    Cell & tissue research 297 (1999), S. 169-186 
    Details
    ISSN: 1432-0878
    Keywords: Key words Adhesion ; Cell lineage ; Development ; Neuromuscular junction ; Serotonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract During the development of the nervous system, numerous neurons connect to form complex networks. In order to build a functional network each neuron has to establish contacts with appropriate target cells, and at these contacts synapses of the right quality and strength have to be formed. Gaining insight into the mechanisms underlying this complex development is an important step towards a better understanding of how the nervous system is formed and behaviour generated. One model system in which synapse formation can be studied at the morphological, physiological and molecular level is that of the fruitfly Drosophila, and insights gained from Drosophila embryos are reviewed here. The first part of this review deals with the neuromuscular junction as the best-known synaptic contact in Drosophila. It describes: (1) its structure, (2) mechanisms underlying the formation of the neuromuscular cell junction and the arborisation of the presynaptic terminal, and (3) our present understanding of signal-dependent and -independent processes during synapse formation at the neuromuscular junction. The last part of this review deals with the question of how particular neurons can adopt specific synaptic properties, stating as an example the development of the neural lineage of NB7-3, which gives rise to two serotonergic neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051345
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Distribution of murine mannose receptor expression from early embryogenesis through to adulthood (1998)
    Springer
    Cell & tissue research 292 (1998), S. 311-323 
    Details
    ISSN: 1432-0878
    Keywords: Key words Mannose receptor ; Macrophage-specific antigen F4/80 ; Macrophages ; Endothelial cells Embryogenesis ; Development ; Immunohistochemistry ; Mouse (C57Black/6 ; BALB/c)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The mannose receptor is a 175-kDa transmembrane glycoprotein that appears to be expressed on the surface of terminally differentiated macrophages and Langerhans cells. The ectodomain of the mannose receptor has eight carbohydrate recognition domains. The receptor recognizes the patterns of sugars that adorn a wide array of bacteria, parasites, yeast, fungi, and mannosylated ligands. Clearance studies in whole animals have localized radiolabeled ligands, such as mannosylated bovine serum albumen, not only to macrophages, but also to liver sinusoidal endothelial cells. Hitherto, there has been no comprehensive analysis of expression of the mannose receptor in embryonic and adult mouse tissues. In this study, we have undertaken a systematic survey of the expression of the mannose receptor from early embryogenesis through to adulthood. The mannose receptor is expressed on tissue macrophages throughout the adult mouse as expected. However, the mannose receptor is first observed on embryonic day 9 on cells that line blood island vessel walls in the yolk sac. The mannose receptor is localized on sinusoidal endothelial cells in embryonic liver by embryonic day 11 and in bone marrow at embryonic day 17. This pattern persists in these organs throughout embryogenesis into adulthood when sinusoidal endothelial cells of lymph nodes also express the mannose receptor. The receptor is also found on lymphatic endothelial cells of small intestine. In contrast, sinusoids of spleen and thymus do not express mannose receptor antigen. This study demonstrates that the mannose receptor is expressed on tissue macrophages and on subsets of vascular and lymphatic endothelial cells. Thus, the mannose receptor maybe a marker of the so-called reticuloendothelial system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051062
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    The neuronal system of the saccus vasculosus of trout (Salmo trutta fario and Oncorhynchus mykiss): an immunocytochemical and nerve tracing study (1997)
    Springer
    Cell & tissue research 288 (1997), S. 497-507 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Hypothalamus ; GABA ; Neuropeptide Y ; Immunocytochemistry ; Development ; ontogenetic ; Oncorhynchus mykiss (Teleostei) ; Salmo trutta fario (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The neuronal system of the saccus vasculosus of two species of trout was studied with immunocytochemical methods and carboindocyanine-dye (DiI) tract-tracing. The cerebrospinal-fluid-contacting neurons of the saccus were immunoreactive for gamma-aminobutyric acid (GABA), glutamic acid decarboxylase (GAD), and neuropeptide Y (NPY). Immunostaining of alternate sections of the saccus vasculosus of fry with anti-GAD and anti-NPY indicated that these substances were colocalized. The tractus sacci vasculosi and the neuropil of the nucleus sacci vasculosi were also immunoreactive to these substances. The GABA, GAD, and neuropeptide Y immunoreactivity of the saccus vasculosus system appeared early in trout ontogeny. After applying DiI to various levels of the tractus sacci vasculosi of adult trout, we observed massive bilateral saccular projections to the nucleus sacci vasculosi and could follow the course of the sacco-thalamic tract. This tract extended in the subependymal region of the thalamus rostral to the nucleus sacci vasculosi and split into two small tracts that reached the subhabenular-preoptic region. Sacco-thalamic fibers formed extensive periependymal plexuses along their trajectory. Interestingly, no clear evidence of the existence of a saccopetal system was obtained. On the basis of these results, we postulate that the saccus vasculosus system modulates the function of centers of the posterior tubercle and periventricular thalamus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050835
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Assessment of contrast sensitivity in kittens after the critical developmental period (1998)
    Springer
    Neuroscience and behavioral physiology 28 (1998), S. 198-200 
    Details
    ISSN: 1573-899X
    Keywords: Development ; kitten ; contrast sensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Spatial contrast sensitivity was measured in kittens aged 6, 9, and 12 months and in adult cats. Cats had to open one of two small windows, which had a photograph of a grid, in order to obtain food reinforcement. The nonreinforced stimulus was a photograph of a uniform field of the same mean luminance. Visual acuity was constant in kittens aged 6 to 12 months. However, six-month-old kittens had low contrast sensitivity at low spatial frequencies (〈0.6 cycles/degree). At the age of nine months, contrast sensitivity over this range increased, though the level seen in adult cats was reached only at the age of 12 months. It is suggested that the increase in contrast sensitivity occurring after the critical developmental period in kittens reflects maturation of higher-order cortical fields involved in the process of recognition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02461967
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Heart rate responses to altered ambient oxygen in early (days 3–9) chick embryos in the intact egg (1999)
    Springer
    Journal of comparative physiology 169 (1999), S. 85-92 
    Details
    ISSN: 1432-136X
    Keywords: Key words Early chick embryos ; Heart rate/heart rate responses ; Hypoxia/hyperoxia ; Development ; Bradycardia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Normal heart rate (HR), and the HR responses to hypoxia and hyperoxia during early heart development in chick embyros have not been studied in detail, particularly in undisturbed embryos within the intact egg. HR was measured in day 3–9 chick embryos at 38 °C using relatively noninvasive impedance cardiography. Embryos were exposed to air (control) and to hypoxic (10% O2) or hyperoxic (100% O2) gas for a 2-h or 4-h period, during which HR was continually monitored. Control (normoxic) HR increased from about 150 beats per min (bpm) on day 3 to about 240 bpm on days 7–9. HR in very early embryos showed a variety of moderate responses to hypoxia (all survived), but as development progressed beyond day 6, hypoxic exposure induced a profound bradycardia that frequently terminated in death before the end of the measurement period. In contrast to the marked developmental changes in hypoxic sensitivity, HR showed little response to hyperoxia throughout development, suggesting no “hypoxic drive” to HR. We speculate that hypoxia has little effect early in development because of the embryo's small absolute O2 demand, but as the embryo grows, hypoxia represents a progressively more severe perturbation. Although general trends were identified, there was considerable variation in both HR and HR responses to ambient O2 changes between individuals of the same developmental stage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003600050197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    The susceptibility of terrestrial gastropods to experimental infection withElaphostrongylus rangiferi Mitskevich (Nematoda: Metastrongyloidea) (1980)
    Springer
    Parasitology research 62 (1980), S. 7-14 
    Details
    ISSN: 1432-1955
    Keywords: Elaphostrongylus rangiferi ; Rangifer tarandus ; Gastropods ; Susceptibility ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Sixteen species of terrestrial gastropods, collected at Tromsöya, northern Norway, were experimentally brought into contact with first stage larvae ofElaphostrongylus rangiferi, a parasite causing neurological disorders in reindeer,Rangifer tarandus (L.). All species were susceptible to infection but there were considerable variations in incidence and intensity of infections and in the development of the nematode in the different gastropod species. InDiscus ruderatus, Arion silvaticus, Deroceras laeve, Euconulus fulvus, andTrichia hispida, development to infective third stage larvae took about 20 days at 20°C. InSuccinea pfeifferi, Deroceras reticulatum andArianta arbustorum development was somewhat slower. InCochlicopa lubrica, Arion subfuscus, A. hortensis, Vitrina pellucida, Nesovitrea spp., andClausilia bidentata, only small numbers of larvae developed and at a very slow rate. InVertigo lilljeborgi andPunctum pygmaeum, the larvae did not develop. Growth in length ofE. rangiferi inD. ruderatus was rapid and continuous up to the second molt (about 15 days postinfection). Thereafter there was a slower growth rate. Tissue reactions against the infection were observed in eleven of the gastropod species. No obvious relationship between the degree of tissue reactions and susceptibility to infection was found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00925362
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    The surface fine structure of the ependymal lining of the lateral ventricle in rats with hereditary hydrocephalus (1977)
    Springer
    Cell & tissue research 179 (1977), S. 121-129 
    Details
    ISSN: 1432-0878
    Keywords: Lateral ventricle, rat ; Hydrocephalus ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ependyma of the lateral ventricle of rats with hereditary hydrocephalus was studied using scanning electron microscopy. Normal rats from the same litters were used as control animals. The surface morphology of the lateral ventricle of normal rats corresponded to results reported by other authors. The most prominent changes in the surface morphology of the ependyma of the hydrocephalic rats were seen in the cilia. They were shortened, fewer in number and clumped or matted. The surface of the ependymal cells was flattened and contained small, irregular projections. The number of large supraependymal cells, regarded as neurons, appeared to have diminished in the hydrocephalic rats. The number of supraependymal macrophages was greatly increased in these rats, suggesting the existence of an ependymitis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00278467
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Differentiation of slow and fast muscles in chickens (1977)
    Springer
    Cell & tissue research 180 (1977), S. 211-222 
    Details
    ISSN: 1432-0878
    Keywords: Muscles ; Enzymes ; Chicken ; Nerve ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The development of the characteristic histochemical appearance of the slow anterior latissimus dorsi (ALD) and fast posterior latissimus dorsi (PLD) was studied in chickens during embryonic development as well as during regeneration of minced muscle. 2. During embryonic development the activity of the oxidative enzyme succinic dehydrogenase (SDH) is higher in the slow ALD muscle already at 16 days of incubation. At this time the fast PLD has a higher activity of the glycolytic enzyme, phosphorylase. Although the histochemical appearance of the two types of muscle is already different at 16 days, their contractile speeds are still similar. No difference in myosin ATP-ase was found in the two muscles in young embryos but in 20-day old embryos the two muscles became distinctly different when stained for this enzyme. 3. When PLD muscles in hatched chickens redeveloped during regeneration in place of ALD the histochemical characteristics of the regenerated muscle resembled ALD, and when ALD regenerated in place of PLD it resembled PLD. 4. It is concluded that the histochemical characteristics of slow and fast muscles become determined during early development, even before any difference in contractile properties can be detected and that they are determined by the nerve.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231953
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Development of the filiform hairs on the cerci of Gryllus bimaculatus Deg. (Saltatoria, Gryllidae) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 1-24 
    Details
    ISSN: 1432-0878
    Keywords: Insect sensillum ; Mechanoreceptor ; Development ; Ultrastructure ; Gryllus bimaculatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The filiform hairs, mechanoreceptors of Gryllus, pass through six developmental stages during the last larval stage. The cytoplasm of their sense cells suggests intensive synthesis of protein for cellular metabolism and intercytoplasmic exchange of material via glial evaginations. Ultrahistochemical tests demonstrated acid phosphatase in the lysosomes as well as in components of the Golgi apparatus. There was no significant change in the appearance of the sense cell cytoplasm, indicating a maintained functional state also during molting. The new cuticular apparatus is formed after apolysis by the three enveloping cells. Formation of the replacement hairs is initiated by a cytoplasmic outgrowth of the trichogen cell. During morphogenesis of the new hair, the microtubules serve as a cytoskeleton and probably control the flow of vesicles, which contain phenol oxidase, also demonstrated in the Golgi apparatus, and are incorporated into the new cuticle. Bundles of microfibrils are involved in the surface sculpturing of the replacement hair. The trichogen cell also forms a number of structural elements, e.g. the “cup” and “strut” marked geometric peculiarities of which indicate that they are important in the spatial orientation of the dendrite and thus also in transduction. Reduction of the apical cell membrane of the tormogen cell after apolysis permits unrestricted growth of the new hair into the exuvial space. The tormogen cell participates in the formation of the joint membrane, parts of the socket and the articulation of the hair.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220615
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Ciliary function of the frog oro-pharyngeal epithelium (1977)
    Springer
    Cell & tissue research 178 (1977), S. 267-278 
    Details
    ISSN: 1432-0878
    Keywords: Ciliated epithelium, frog ; Cilia ; Coordination ; Mucous transport ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The palate epithelium of the frog was examined by scanning electron microscopy, light microscopy and high speed cine micrography. The cilia remain stationary for much of the time in the end-of-effective stroke position. Each beat cycle begins with a forwardly-directed recovery stroke lasting about 60 ms, followed by an effective stroke towards the oesophagus lasting about 12 ms. Activity can often be correlated with the presence of mucus, which is carried as strands on the tips of the ciliary effective strokes whilst the recovery strokes move beneath the mucus. Coordination of ciliary activity was very variable; local antiplectic metachrony of the recovery strokes could almost always be seen, and on very active epithelia effective strokes were associated with approximately diaplectic waves (either to left or right), but any particular pattern of coordinated activity was transient and quickly transformed to another pattern. Beating and coordination of these short cilia were compared with those of cilia propelling water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219053
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Surface morphology of taste buds in catfish barbels (1977)
    Springer
    Cell & tissue research 178 (1977), S. 375-384 
    Details
    ISSN: 1432-0878
    Keywords: Taste buds ; Fishes ; Neuroepithelium ; Microvilli ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary External taste buds abound on barbels of the adult catfish Corydoras arcuatus. When examined by scanning electron microscopy, they are visualized as a series of punctate, conical elevations projecting from the general surface epithelium. All taste buds were found to be of one type. Both their external and internal surface features could be clearly elucidated on intact barbels and in barbels fractured transversely at various positions along their length. An extensive nerve terminal network penetrates the base of each taste bud. Two populations of elongated cells bearing prominent microvilli project through the central pore at the tip of each bud. One set of microvilli is thicker, longer and more club-shaped than its counterpart. While both are randomly distributed within each central pore, the small, short microvilli appear to outnumber the larger ones. A third population of cells, devoid of any apical microvilli, was also seen in some of the taste buds examined internally. These cells do not project to the external surface and are interpreted as “basal” cells described in previous light and transmission electron microscope studies of taste buds in other vertebrate species. The functional significance of some of these morphological findings is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218701
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Vascularization of the pars distalis of the hypophysis in the toad, Bufo bufo (L.) (Amphibia, Anura) (1977)
    Springer
    Cell & tissue research 179 (1977), S. 1-10 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysis, pars distalis ; Bufo bufo (L.) ; Vascularization ; Corrosion casts ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The vascularization of the pars distalis of the hypophysis of the toad, Bufo bufo (L.), was studied by the traditional method of injecting a mixture of India-ink and gelatine into the circulatory system of the head via the arteria carotis communis. Further, methyl-methacrylate corrosion casts of the brains were made; the hypothalamo-adenohypophysial region of these corrosion casts was studied with the scanning electron microscope. The results showed that the portal vessels which arise from the median eminence do not supply distinct areas in the pars distalis as is supposed by the point-to-point-hypothesis. The portal vessels enter the ventro-median region of the pars distalis and branch off into a three-dimensional network of the secondary capillary plexus of the pars distalis. The plexus is made up mostly by four- to six-sided meshes. This angioarchitecture guarantees an optimal supply of the glandular cells of the pars distalis with nutritional factors and releasing hormones, on the one hand, and facilitates the removal of the hormones which are released by these cells, on the other hand. The venous drainage of the pars distalis is exerted mainly by two large veins, which bilaterally leave the dorso-lateral region (venous pole) of the pars distalis and by a few small veins, which drain into the wide, sinus-like vessel, which curves around the dorso-caudal region of the pars distalis and joins bilaterally the vena hypophysea transversa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00278459
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    In vivo and in vitro formation of the junctional complex in choroid epithelium (1977)
    Springer
    Cell & tissue research 181 (1977), S. 427-441 
    Details
    ISSN: 1432-0878
    Keywords: Chick embryo ; Choroid epithelium ; Junctional complex ; Development ; Freeze-etching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The Junctional complex of choroid epithelial cells was studied during in vivo formation, disaggregation after trypsin treatment, and in vitro reaggregation. The in vivo formation begins with the occurrence of amorphous patches of particles followed by the formation of small particulate rows and polygonal-ordered particle assemblies. Further arrangement of the zonula occludens continues with the confluence of particles and smooth contoured ridges. At the 9th day stage a fully developed zonula occludens has developed. In a subsequent step nexus become integrated within the tight junction formation. Disaggregation after trypsination results in fragmentation of the zonulae occludentes. Parts of the disassembling aggregates become incorporated in vacuoles indicating an endocytotic mode of “digestion”. The in vitro reconstruction of the zonula occludens proceeds from remnants of the former zonula occludens. On the 3rd to 4th day of cultivation mature tight junctions are visible. In vitro integrations of nexus were observed during a later phase. On the 7th day, cultivated choroid epithelial cells reveal well differentiated Junctional complexes consisting of continuous zonulae occludentes and integrated gap junctions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221766
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    A scanning electron microscopic survey of the brain ventricular system of the female armadillo (1977)
    Springer
    Cell & tissue research 183 (1977), S. 531-539 
    Details
    ISSN: 1432-0878
    Keywords: Brain ventricles ; Armadillo ; Ependyma ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The scanning electron microscope was used to survey the brain ventricular system of the female armadillo (Dasypus novemcinctus) with emphasis on the third ventricle. The walls of the lateral ventricles, aqueduct, and fourth ventricle are covered by long cilia. In the lateral ventricle, the cilia are arranged in groups; but in the aqueduct and fourth ventricle, they are evenly placed over the cellular surfaces. The ependymal cells of the third ventricle are densely ciliated except for the organum vasculosum and infundibular recess. The non-ciliated luminal surface of these areas has a pebblestone appearance punctuated by numerous microvilli and two types of supraependymal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225665
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Discocilia—A new type of kinocilia in the larvae of Lanice conchilega (Polychaeta, Terebellomorpha) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 271-280 
    Details
    ISSN: 1432-0878
    Keywords: Kinocilia ; Discocilia ; Lanice conchilega ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Ein modifizierter Typ von Kinocilien wurde bei der Aulophoralarve des sedentären Polychäten Lanice conchilega gefunden. Für ihn wird die Bezeichnung „Discocilium” vorgeschlagen. Der einzige strukturelle Unterschied zu konventionellen Kinocilien besteht in der Ausbildung eines Köpfchens. Dieses Köpfchen wird vom distalen Ende des Cilienschaftes gebildet, der zu einer Öse gebogen ist, die von der Cilienmembran überzogen wird. Drei Haupttypen von Discocilien können unterschieden werden: a, Cilien mit geradem Axonem, deren Köpfchen durch eine Anschwellung der Membran entstehen, b, Cilien mit Köpfchen mit seitlichem gebogenem Axonem, c, Cilien, in denen das Axonem eine geschlossene Öse bildet. Die Discocilien sind nach dem verbreiteten 9+2 Filamentmuster aufgebaut. Ihr Köpfchen enthält keine Sekrete, es erscheint elektronenoptisch leer. Aufgrund ihrer Anordnung können zwei Typen von Discocilien unterschieden werden, nämlich isolierte Büschel, besonders am Vorderende, und segmentai angeordnete Cilienreihen. Ein möglicher Bildungsmodus der Discocilien wird beschrieben.
    Notes: Summary A modified type of kinocilia has been found in the Aulophora-larva of the sedentarian polychaete Lanice conchilega. For this newly described cilium type the term “discocilium” is proposed. The only structural difference from usual locomotory cilia is the tip, which possesses a discoidal head. The head is formed from the terminal part of the cilium shaft, which is bent to give rise to a loop-like ring covered by the ciliary membrane. Three types of discocilia can be distinguished: a) discocilia having swollen, bulblike heads with a central straight axoneme; b) discocilia having heads with a curved lateral axoneme and c) discocilia in which the axoneme forms a loop. The internal structure shows the usual 9+2 arrangement of the filaments. The head shows no signs of secretion; it appears structureless in electron microscopical examination. There are two kinds of discocilia arrangements: 1) isolated bunches of cilia especially at the tentacles and in the frontal region, and 2) segmental dorsal rows of cilia. The possible formation of discocilia is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224370
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Scanning electron microscopic analysis of the linings of the fourth ventricle in the domestic fowl (1979)
    Springer
    Cell & tissue research 197 (1979), S. 169-173 
    Details
    ISSN: 1432-0878
    Keywords: Fourth ventricle ; Ependyma ; Scanning electron microscopy ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Surface features of the ependymal linings of the fourth ventricle in the fowl were analyzed employing the scanning electron microscope (SEM). On the floor of the median sulcus, each ependymal cell has a solitary cilium, whereas on both sides of the sulcus, cilia are so densely distributed that the details of the underlying cell surface are usually obscured. On the roof of the fourth ventricle, except for the surface of the ciliated groove where numerous cilia are present, the ependymal cells are polygonal in shape, and the center of each cell possesses an aggregate of ten to twenty cilia. Cell surfaces of the choroid tela are entirely covered with delicate microvilli and possess clumped cilia. The ependymal cell surfaces of the area postrema are dome-like in shape. Each ependymal cell has a solitary cilium and shows a smooth surface free of microvilli.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233562
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...