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  • Light and electron microscopy  (47)
  • Innervation  (42)
  • Synapses  (37)
  • Springer  (124)
  • 2005-2009
  • 1970-1974  (124)
  • 1950-1954
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  • Springer  (124)
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Year
  • 101
    Electronic Resource
    Electronic Resource
    Elektrisches Organ vonGnathonemus (Mormyridae) (1971)
    Springer
    Cell & tissue research 122 (1971), S. 538-563 
    Details
    ISSN: 1432-0878
    Keywords: Electric Organs ; Mormyridae ; Fine structure ; Innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Die drei Arten der GattungGnathonemus (Gn. petersii, moorii, stanleyanus) besitzen, wie alle Arten der Familie Mormyridae, zwei Paar elektrische Organe, die symmetrisch auf jeder Seite der Wirbelsäule zwischen der Caudal-, Dorsal- und Afterflosse liegen. Jedes Organ ist aus einer Serie von 70–170 elektrischen Platten zusammengesetzt. 2. Die Stiele der elektrischen Platten enthalten keine Nervenfortsätze. Die elektromotorischen Nervenfasern innervieren die Endanschwellung der Stiele, indem sie sich unverzweigt in einem kurzen marklosen Endabschnitt in eine Vertiefung des Elektroplasmas einfügen. 3. Die Elektroplasmamembran umgibt ohne Ausnahme die Stiele und die elektrische Platte. Sie ist sowohl auf der cranialen als auch auf der caudalen Seite der Platte tief eingebuchtet. Dadurch ist deren Oberfläche stark vergrößert. Im Inneren der Platte befindet sich quergestreifte Muskulatur. 4. Die motorischen und sensiblen Nervenfasern unterscheiden sich deutlich in ihrem Durchmesser. 5. Die Zahl der Nervenzellen in den Spinalganglien ist im elektrischen Organ um ein Mehrfaches größer als in den Segmenten der vor dem elektrischen Organ liegenden Rumpfmuskulatur. 6. Die Rekonstruktion der peripheren sensiblen Nerven eines Segments (aufgrund elektronenmikroskopischer Untersuchungen) ergibt die Tatsache, daß diese, mit Ausnahme von zwei freien Nervenendigungen in der Haut und freien Nervenendigungen im dorsalen Myoseptum, vor allem vier große Sehnen an der Seite des elektrischen Organs innervieren. 7. Die Innervationsverhältnisse des elektrischen Organs führen zu der Hypothese, daß die Sehnen im Zusammenhang mit der Funktion des elektrischen Organs sensorische Funktionen besitzen.
    Notes: Summary 1. Three species of the genusGnathonemus (Gn. petersii, moorii andstanleyanus) as all species of the family Mormyridae possess two pairs of electric organs situated symmetrically on each side of the vertebral column between the caudal, dorsal and anal fins. Each organ is composed of a series of 70–170 electroplaques. 2. The stalks of the electroplaques contain no nerves. Unbranched motor nerve fibres innervate the end sections of the stalks by synaptic knobs inserting into cavities of the electroplasma. 3. The electroplasma membrane surrounds the stalk (also in the region where the stalk penetrates through holes in the body of the electroplaque) and the electroplaque. The membrane is deeply indented on the cranial side as well as on the caudal side of the electroplaque. Through this the surface is greatly enlarged. In the inside of the electroplaque are striated muscles. 4. The motor and sensory nerve fibres are clearly different in diameter. 5. The number of the nerve cells in the spinal ganglions is, in the electric organ, about a multiple larger than in the segments of the body muscular system situated in front of the electric organ. 6. The reconstruction of the peripheral sensory nerves of one segment (in view of electron microscopical analyses), reveals that these, with the exception of two free nerve endings in the integument and the free nerve endings in the dorsal myoseptum, mainly innervate four large tendons on the side of the electric organs. 7. The innervation of the electric organs leads to the hypothesis that the tendons, in connection with the function of the electric organs, possess sensory functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00936087
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  • 102
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    Über die Synapsenformen und das Vorkommen von Acetylcholinesterase in der Epiphyse von Bombina variegata (L.), (Anura) (1972)
    Springer
    Cell & tissue research 126 (1972), S. 278-296 
    Details
    ISSN: 1432-0878
    Keywords: Anura ; Pineal organ ; Synapses ; Acetylcholinesterase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung In der Epiphyse von Bombina kommen durch „synaptic ribbons“ gekennzeichnete Synapsen und konventionelle Synapsen vor. Bei den „ribbon“-Synapsen handelt es sich um axodendritische und axosomatische Formen. Die axodendritischen „ribbon“-Synapsen lassen sich aufgrund der Zahl der Dendriten und der „synaptic ribbons“ in 2 Typen gliedern. Es kommen Dendriten vor, die nacheinander in „ribbon“-Synapsen und konventionelle Synapsen einbezogen sind. Neben konventionellen und durch „ribbons“ gekennzeichneten synaptischen Verbindungen finden sich weitere Kontakte zwischen Sinnes- und Nervenzellen und Interrezeptorkontakte, die jedoch beide nicht als echte Synapsen angesprochen werden können. Anhand der Befunde zur Synaptologie werden Probleme der neuronalen Schaltung der Epiphyse diskutiert. Beim Acetylcholinesterase-Nachweis findet sich das Reaktionsprodukt vor allem in den Neuropilzonen der Epiphyse. Eine eindeutige Zuordnung zu Fortsätzen bestimmter Zelltypen ist nicht möglich. Das Ergebnis des Acetylcholinesterase-Nachweises in der Epiphyse wird mit entsprechenden Befunden in anderen Bereichen des ZNS und in der Netzhaut verglichen.
    Notes: Summary Both conventional and ribbon synapses occur in the pineal organ of Bombina. Ribbon synapses are both axodendritic and axosomatic. Two axodendritic types can be distinguished on the basis of the number of dendrites and synaptic ribbons. Both conventional and ribbon synapses can be formed with the same dendrite. Other contacts, which cannot be classified as true synapses, are also found between sensory cells and nerve cells and likewise between sensory cells. The synaptology of the pineal organ permits a discussion of the problems of its neurocircuitry. Products of the acetylcholinesterase reaction occur mainly in the plexiform layer of the pineal organ. It is not possible to correlate the reaction products with definite cell types. The results of the acetylcholinesterase reaction in the pineal is compared with corresponding findings in other parts of the CNS and in the retina of the lateral eyes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307221
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  • 103
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    The ultrastructure of the A1 sensilla on the posterior surface of the clypeo-labrum of Locusta migratoria migratorioides (R and F) (1972)
    Springer
    Cell & tissue research 134 (1972), S. 539-554 
    Details
    ISSN: 1432-0878
    Keywords: Chemoreceptors ; Locusta ; Clypeo-labrum ; Light and electron microscopy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The A1 sensilla are asymmetric in distribution. Each sensillum contains five bipolar neurons, the distal regions of which extend to the tip of a cuticular cone which has a terminal pore. This was shown with the scanning electron microscope, but was not seen in section. The receptor-lymph cavity of the tormogen cell and the basal cavity of the neurilemma cell contain an electron-dense material unlike other contact chemoreceptors of Locusta prepared for electron microscopy in the same manner. Isolated axons of unknown function occur below the basement membrane and also between epidermal cells surrounding the sensillum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307673
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  • 104
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    Zur Morphologie der Ductuli efferentes des Bullen (1972)
    Springer
    Cell & tissue research 135 (1972), S. 129-148 
    Details
    ISSN: 1432-0878
    Keywords: Ductuli efferentes ; Bull ; Absorption ; Apocrine extrusion ; Light and electron microscopy ; Enzyme cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Epithel der Ductuli efferentes des erwachsenen Bullen ist einschichtig zylindrisch mit gelegentlichen Basalzellen. Die Zylinderzellen lassen sich in Zilienzellen und Hauptzellen untergliedern. Hauptzellen treten vor allem in zwei Funktionsstadien mit unterschiedlichen morphologischen Charakteristika auf: 1. Resorbierende Hauptzellen besitzen einen Saum gleichmäßig langer Mikrovilli, zwischen deren Basen sich ein System aus gewundenen Canaliculi in das apikale Cytoplasma einsenkt. Diese Canaliculi stehen mit „coated“ Vesikeln und größeren resorptiven Vakuolen in Verbindung. Innerhalb der Vakuolen findet ein Abbau von resorbierter testikulärer Flüssigkeit statt. Hieran sind lysosomale Enzyme beteiligt, wie der kräftige Ausfall der histochemischen Reaktionen auf saure Phosphatase, unspezifische Esterasen und β-D-Glucuronidase im Epithel der Ductuli belegt. Unverdaulicher Vakuoleninhalt verdichtet sich zu homogenen,PAS-positiven, eiweißhaltigen, fluoreszierenden, membranlosen, osmiophilen Globuli. 2. Extrudierende Hauptzellen besitzen aufgehellte, mikrovillifreie apikale Cytoplasmaprojektionen, die mit den in ihnen gelegenen Globuli in das Ductuluslumen abgenabelt werden können. Für eine Phagocytose von ganzen oder fragmentierten Spermatozoen durch das Epithel der Ductuli efferentes des Bullen haben sich keine morphologischen Anhaltspunkte ergeben.
    Notes: Summary The ductuli efferentes of the adult bull are lined by a simple columnar epithelium with scattered small basal cells. The columnar epithelium consists of ciliated and non-ciliated cells. Among non-ciliated cells two functional stages with distinct morphological features may be identified: 1. Absorptive cells possess a border of numerous, rather evenly packed microvilli with strong alkaline phosphatase activity. Between the microvilli the apical cell membrane is invaginated to form a system of narrow, coiled canaliculi which are continuous with coated vesicles and large vacuoles. Testicular fluid is reabsorbed into these vacuoles and broken down by means of lysosomal enzymes. So high levels of acid phosphatase, esterases and β-D-glucuronidase are present in the ductuli efferentes epithelium. Undigestible content of absorptive vacuoles is condensed to homogeneous, PAS-positive, protein-positive, osmiophilic, fluorescing, non membrane-bound globules. 2. Non-ciliated cells with light, globules containing projections of the apical cytoplasm. These protrusions are occasionally found pinched off into the ductular lumen. We did not find any morphological evidence for phagocytosis of whole or fragmented spermatozoa by the epithelium of the bovine ductuli efferentes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307093
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  • 105
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    Vergleichende Untersuchungen am Integument von Hetero- und Eutardigraden (1972)
    Springer
    Cell & tissue research 135 (1972), S. 517-538 
    Details
    ISSN: 1432-0878
    Keywords: Integument ; Tardigrada ; Cuticle ultrastructure ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Licht- und elektronenmikroskopische Untersuchungen am Integument vonEchiniscus testudo (Heterotardigrada),Milnesium tardigradum, Hypsibius oberhaeuseri undMacrobiotus hufelandi (Eutardigrada) lassen acht, mindestens jedoch sechs Schichten erkennen, die in Anlehnung an Baccetti und Rosati (1971) benannt werden, wobei eine Homologie beiE. testudo nicht sicher ist. BeiE. testudo bildet die innere sklerotisierte Epicuticula ein Hohlraumsystem, dessen Wände von ca. 150 Å breiten Kanälen durchzogen werden. Die dorsalen Einsenkungen der Panzerplatten besitzen einen zentralen 500 Å breiten Kanal. Ventral ist die äußere Epicuticula mehrfach geschichtet. Ein darunterliegender Röhrchensaum und die weitgehend reduzierte innere Epicuticula lassen andere Permeabilitätseigenschaften vermuten. Die Intracuticula zeigt vertikale Filamente. Wachsschicht und innere Lage der Intracuticula sind morphologisch nicht eindeutig zu identifizieren. Die einschichtige Epidermis ist reich an Lipidtropfen, freien Ribosomen und granulärem endoplasmatischem Reticulum. Manche Zellen sind kontrastreicher. Besondere Cuticula-Bildungen der drei Eutardigraden sind die epicuticulären Einsenkungen vonM. hufelandi, in deren Bereich die innere Epicuticula fehlt, die dorsale und laterale Skulpturierung vonH. oberhaeuseri, die eine Bildung der Epicuticula ist, und die epicuticulären Kanäle vonM. tardigradum. Die Proticula aller untersuchten Tardigraden-Arten besitzt keine Porenkanäle. Die Epidermis vonM. hufelandi besteht aus einem einschichtigen Epithel. Seine Zellen enthalten zahlreiche membranbegrenzte osmiophile Einschlüsse, die die Färbung der Tiere bedingen. Einzelne Zellen fallen durch ihren hohen Kontrast und zahlreichere Organellen auf. Die Cuticula der Eutardigraden zeigt in allen Fällen eine morphologisch vergelichbare Schichtenfolge. Die Cuticula vonE. testudo, die Besonderheiten aufweist, kann jedoch aufgrund charakteristischer Merkmale (z. B. die äußere Lage der Intracuticula) vielleicht in den Vergleich einbezogen werden.
    Notes: Summary The structure of the integument ofEchiniscus testudo (Heterotardigrada),Milnesium tardigradum, Hypsibius oberhaeuseri andMacrobiotus hufelandi (Eutardigrada) was studied by light and electron microscopy. In all species the cuticle consists of 6–8 layers and can adequately be described following the terminology of Baccetti and Rosati (1971). This perhaps does not apply toE. testudo. InE. testudo the inner sclerotized epicuticle reveals a labyrinthine structure due to lacunae with numerous channels of about 150 Å in diameter. The central canals in the depressions of the dorsal plates have a diameter of 500 Å. The outer epicuticle of the ventral cuticle is formed by several layers. Basally there is a tubular layer of channels and an almost reduced epicuticle. Thus the permeability of the cuticle is supposed to be altered. In the intracuticle vertically oriented filaments occur. The inner layer of the intracuticle and the wax-layer cannot be properly distinguished. The one-layered epidermis contains many lipid droplets, ribosomes and rough ER. Some of the cells are rather electron-dense. Peculiar cuticular structures inM. hufelandi appear as cup-shaped depressions of the epicuticle, and here the inner epicuticle is absent. A similarly typical feature is the structured and sculptured dorsal and lateral epicuticle ofH. oberhaeuseri and the channels of the epicuticle inM. tardigradum. In all species investigated there are no pore canals in the procuticle. InM. hufelandi there is a single layer of epidermal cells, which contain many osmiophilic grana ensheathed by membranes. These grana cause the colour of the animal. Some of the cells contain more organelles and ribosomes and show a strong contrast. In spite of some cuticular peculiarities inE. testudo, perhaps this Heterotardigrade species fits into the general pattern of cuticle morphology of Tardigrada.
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    URL: http://dx.doi.org/10.1007/BF00583434
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    Responses of prolactin cells of two euryhaline marine fishes, Gillichthys mirabilis and Platichthys stellatus, to environmental salinity (1973)
    Springer
    Cell & tissue research 136 (1973), S. 153-167 
    Details
    ISSN: 1432-0878
    Keywords: Prolactin ; Adenohypophysis ; Osmoregulation ; Teleosts ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Changes in the prolactin cells of the euryhaline marine teleosts Gillichthys mirabilis and Platichthys stellatus were studied by light and electron microscopy after transfer from sea water to fresh water. In seawater fish the secretory granules were smaller and the cellular organelles poorly developed. Within 3 hours after transfer to fresh water, the prolactin cells of Gillichthys exhibited definite functional activation: exocytosis of granules and development of rough endoplasmic reticulum (RER), Golgi systems and mitochondria. Concurrently, plasma sodium fell from about 172 meq/l to about 133 meq/l. As adaptation to fresh water progressed, prolactin cells of Gillichthys showed greater prominence of cellular organelles but granule storage was not detected even 10 days after transfer. Platichthys adapted to fresh water for 10 days showed RER in an expanded state containing irregular electron-dense material which was not seen in Gillichthys. Plasma sodium levels were much lower than in the controls. These results were in contrast to those obtained from euryhaline freshwater fishes such as Poecilia and Oryzias. Although the prolactin cells of euryhaline marine fish exhibited intense secretory activity when transferred into fresh water, the secreted prolactin per se appeared to be insufficient to maintain plasma sodium at seawater levels.
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    URL: http://dx.doi.org/10.1007/BF00307436
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    Rectal ultrastructure in salt- and freshwater mosquito larvae in relation to physiological state (1973)
    Springer
    Cell & tissue research 138 (1973), S. 1-22 
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    ISSN: 1432-0878
    Keywords: Mosquitoes-Aedes ; Rectum ; Fine structure, function, comparison ; Salt-adaptation, osmoregulation ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A comparison of rectal morphology and ultrastructure is made between a freshwater (A. aegypti) and salt water (A. campestris) species of mosquito larvae, and between A. campestris larvae producing hyper- and hyposmotic urine. The epithelium of A. aegypti contains one cell type characterized by infolding of both the apical and basal membranes, straight lateral borders, and evenly distributed mitochondria. The rectum of A. campestris contains distinct anterior and posterior regions, each made up of a single cell type. These two regions can be distinguished on the basis of cell thickness, depth of apical infolding and distribution of mitochondria. The anterior region is similar to the rectum of A. aegypti, while the posterior region is considered unique to the salt-water species and hence probably is associated with the formation of hyperosmotic urine. In A. campestris, the apical (rather than lateral or basal) membranes are probably the site of hyperosmotic urine production. Two possible mechanisms for this process are discussed.
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    URL: http://dx.doi.org/10.1007/BF00307074
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  • 108
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    The fine structure of the pancreatic nerves of the domestic fowl (1973)
    Springer
    Cell & tissue research 136 (1973), S. 501-510 
    Details
    ISSN: 1432-0878
    Keywords: Pancreas ; Fowl ; Innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the pancreatic nerves of the domestic fowl has been studied. Naked axon beadings were found in membranous contact with endocrine as well as exocrine cells. From an anatomical point of view it seems reasonable to suggest that the endocrine glands might be subjected to some influence of the autonomic nervous system.
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    URL: http://dx.doi.org/10.1007/BF00307366
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  • 109
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    Elektronenmikroskopische Untersuchungen über die Zytoarchitektur des Gehirns vonBranchiostoma lanceolatum (1973)
    Springer
    Cell & tissue research 139 (1973), S. 511-532 
    Details
    ISSN: 1432-0878
    Keywords: Brain ; Cytoarchitecture ; Branchiostoma ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Gehirn vonBranchiostoma lanceolatum wurde licht- und elektronen-mikroskopisch untersucht. Der rostral gelegene Ventrikel wird von unterschiedlich gebauten, prismatischen Epithelzellen umgeben, unter denen neben den Pigmentzellen und den sekret-bildenden Infundibulumzellen vor allem dorsal und ventral gelegene Elemente mit ungewöhnlich langen, zilienähnlichen apikalen Fortsätzen auffallen, die vermutlich Rezeptorzellen entsprechen. Nach caudal schließt sich dem Ventrikel der schmale Zentralkanal an, der von Tanyzytengliazellen ausgekleidet wird. Ihre basalen filamenthaltigen Fortsätze ziehen bis zur Oberfläche des ZNS und bilden hier Füßchen aus. Zwischen diesen Ependymzellen erreichen apikale Fortsätze von tiefergelegenen Zellen das Lumen des Zentralkanals. Die Zahl der um den Zentralkanal gelegenen Neurone nimmt im Gehirn von rostal nach caudal ab. Die Perikaryen dieser Neurone sind vor allem durch ihren hohen Gehalt an Glykogen und verhältnismäßig zahlreichen granulären Einschlüssen gekennzeichnet. Eine ventral gelegene Gruppe von großen, ergastoplasmareichen Nervenzellen enthält relativ große Granula, die vermultlich neurosekretorischen Elementargranula entsprechen. Dorsal kommen neben den großen Josephschen Zellen ependymale Zellen vor, deren Zellapex mit zahlreichen Lamellen versehen ist. Auch sie stellen vermutlich Lichtrezeptoren dar. Das peripher lateral und ventral gelegene Neuropil setzt sich aus Fasern zusammen, die nicht von den Gliazellen umgeben sind und die in ihrer Mehrzahl Granula enthalten. Es werden 6 (?) Granulatypen unterschieden. Außerdem lassen sich vor allem in der Peripherie Fasern mit Mikrotubuli und Filamenten erkennen. Die Riesenfasern enthalten außer einzelnen Organellen unstrukturiert erscheinendes Zytoplasma. Synapsenähnliche Kontakte sind relativ selten und einfach gebaut.
    Notes: Summary The brain ofBranchiostoma lanceolatum has been investigated with the light-and electron microscope. The cranially located ventricle is surrounded by various types of prismatic epithelial cells among which—beside the anterior pigment-cells and the mucus producing infundibular cells—elements bearing unusually long apical cilium-like processes are particularly striking. They can be found in the dorsal and ventral wall of the ventricle and presumably represent receptor cells. The ventricle is caudally replaced by the narrow central canal which is lined by tanycyte-like glia cells, whose filamentous basal processes reach the surface of the CNS where they terminate in broad foot-like structures. Between these ependymal cells apical processes of light, granule-containing cells reach the lumen of the central canal. The number of neurons which are all concentrated around the central canal, decreases in caudal direction. Their perikarya are characterized by granular inclusions and large amounts of glycogen particles. A ventrally situated group of big ER-rich neurons contains granules which presumably correspond to neurosecretory elementary granules. Dorsally beside the large Joseph-cells lamellated cells occur, which possibly also represent lightreceptor cells. The neuropile which predominantly occurs in the lateral and ventral and ventral periphery of the CNS consists of densely packed fibres which are not surrounded by glia cells and the majority of which contains granular or vesicular inclusions. 6 (?) types of granules and vesicles are to be distinguished. In addition, fibres containing microtubules and filaments occur. They are mainly to be found in a marginal position. The giant fibres contain beside scarce organelles structureless light cytoplasm. Synaptoid contacts are comparatively rare and of simple structure.
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    Nigro-neostriatal projection (1973)
    Springer
    Cell & tissue research 138 (1973), S. 333-344 
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    ISSN: 1432-0878
    Keywords: Substantia nigra and striatum (rat, cat) ; Stereotactic electrolysis ; Degeneration ; Dopamine fluorescence ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nigro-neostriatal projection was investigated in albino rats and cats with silver impregnation, fluorescence histochemistry and electron microscopy. After unilateral stereotactic electrolysis in the substantia nigra the dopamine fluorescence of ipsilateral neostriatum is markedly reduced. As shown by silver impregnation and electron microscopy, fine terminals and axons are degenerated in the same region. These observations suggest that the nigro-neostriatal pathway may be composed of the fine dopaminergic axons of the nerve cells of unilateral substantia nigra.
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    URL: http://dx.doi.org/10.1007/BF00307097
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    Le Système Nerveux des Cténaires (1973)
    Springer
    Cell & tissue research 137 (1973), S. 223-250 
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    ISSN: 1432-0878
    Keywords: Nervous system ; Ctenophores ; Nerve-net, Nervous concentration ; Synapses ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A subectodermal nerve-net is demonstrated in ten species of Ctenophores by means of either Methylene Blue vital staining or silver impregnation. There is no evidence of subendodermal nerve-net. The ectodermal nerve-net displays a characteristic polygonal pattern which is thought to result from morphogenetic events. Both bipolar and tripolar neurones occur. Three types of concentrations of nervous tissue are described: a) a high accumulation of nervous perikarya at the aboral sensory pole; b) a noticeable densification of the net along the eight meridional ciliary strands of every species, and around the lips of Beroidea; c) in the Cydippids Pleurobrachia and Hormiphora two thick strands of fibers and neurones interconnecting the aboral organ and the tentacles: the tentacular nerves. Ultrastructural evidence is given for the presence of nervous elements under and amidst ectodermal epithelial cells. Three features allow the recognition and characterization of neurites and neurones: a) numerous clear and/or granulated vesicles; b) microtubules in variable amounts; c) frequent and highly differentiated synaptic contacts. The very peculiar arrangement of the presynaptic elements is observed in all the species of Ctenophores so far studied. These synaptic contacts suggest chemical transmission in the nerve-net. On the basis of ultrastructural evidence the author refutes the nervous nature previously attributed to the ciliated cells of the meridional grooves. A parallel is drawn between nervous systems of Cnidaria and Ctenophora.
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    URL: http://dx.doi.org/10.1007/BF00307432
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  • 112
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    Fluorescence and electron microscopy of the monoamine-containing cells in the turtle heart (1973)
    Springer
    Cell & tissue research 140 (1973), S. 25-37 
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    ISSN: 1432-0878
    Keywords: Heart innervation (Turtle) ; Monomamine-containing cells ; Synapses ; Fluorescence and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fluorescence and electron microscopy of the turtle heart indicates the presence of monoamine-containing, granulated cells in the wall of venous sinus and near the openings of the aortic trunks. These cells occur in clusters and are always in association with nerve fibers and/or ganglion cells within the turtle heart. Vesiculated axon terminals make a synaptic contact with the cytolemma of the granulated cell which in turn makes a synapse to the processes from the other granulated cell and to the cardiac nerve fibers. The close contact occurs also between the granulated cell process and the smooth muscle cell membrane in the wall of large vessels. The granulated cell has no special relationship to the blood capillaries. The significance of these results is discussed in relation to nervous control of the cardiac activity of the turtle.
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    URL: http://dx.doi.org/10.1007/BF00307057
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    The development of synapses in vitro between previously dissociated chick spinal cord neurons (1973)
    Springer
    Cell & tissue research 140 (1973), S. 203-216 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Development ; Chick embryo ; Cell culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The formation and development of synaptic contacts between dissociated chick spinal cord neurons has been investigated. By the 6th day in vitro “immature” profiles with few vesicles were observed. By 14–18 days “mature” types with numerous vesicles were found, indistinguishable from those of newly hatched chick spinal cord. After this period degeneration occurred, and was especially marked in the post-synaptic element. Such degeneration could be postponed by the addition of small numbers of somatic muscle cells. The Kanaseki and Kadota (1969) technique was applied to the study of coated vesicles at various stages of synaptic development.
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    URL: http://dx.doi.org/10.1007/BF00306695
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    The aquatic egg of Nymphula nymphaeata (Lepidoptera: Pyralidae) (1974)
    Springer
    Cell & tissue research 149 (1974), S. 473-479 
    Details
    ISSN: 1432-0878
    Keywords: Aquatic eggs ; Insects ; Envelopes ; Respiration ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The aquatic egg of Nymphula has no trabecular layer and no aeropyles. Four tubular micropyles only traverse the anterior part of the chorion. Presumably, the egg contains a sufficient quantity of air to allow the development of the caterpillar when the egg is immersed in paraffin oil. Under the chorion, the vitelline membrane possesses crypts and furrows which seem filled by air. This air can enter through the permeable regions of the vitelline membrane. The mucus, between the chorion and the under surface of the leaf, may constitute an external air reserve dependent on photosynthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223026
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    The innervation of purkinje fibres in the atrium of the avion heart (1974)
    Springer
    Cell & tissue research 150 (1974), S. 57-66 
    Details
    ISSN: 1432-0878
    Keywords: Purkinje Fibres ; Avian heart ; Innervation ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the Purkinje fibres in the atrium of the heart of the adult fowl was investigated by light microscopy, using the Champy-Maillet OsO4-ZnI2 technique and the cholinesterase reaction and by electron microscopy. After impregnation of the tissue with OsO4-ZnI2, the dark-stained nerve fibres were clearly visible on the unstained Purkinje fibres. In the upper part of the posterior wall of the right atrium, the diffuse portion of the conducting system is especially richly innervated by varicose and smooth nerve fibres. Some of these fibres are cholinesterase-positive. The terminal axons run in the space between the Purkinje fibres and the fibrocytic envelope. They are either naked or accompanied by Schwann cell processes. In addition to varicosities containing granular vesicles, there are varicosities containing agranular vesicles with oval profiles. In the “en passant” synapses, the width of the synaptic cleft between a varicosity and the Purkinje cell is about 600 Å. The innervation of the Purkinje fibres appears more like the innervation of smooth muscle than that of striated skeletal muscle. The possible role of Purkinje fibres as mechanical receptors is discussed.
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    URL: http://dx.doi.org/10.1007/BF00220380
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    Hypothalamic projections to the amygdala in the cat (1974)
    Springer
    Cell & tissue research 151 (1974), S. 499-508 
    Details
    ISSN: 1432-0878
    Keywords: Limbic system ; Cat ; Amygdaloid body ; Hypothalamus ; Stereotaxic lesions ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to determine the origin of the hypothalamo-amygdaloid connections in the cat, small lesions were placed at various rostro-caudal levels of the hypothalamus. The animals were sacrificed after a period of 4, 8 or 11 days and the brains stained with the Nauta (1957), Fink and Heimer (1967) or Wiitanen (1969) method for the demonstration of degenerating axons and their terminals. It was observed that the anterior hypothalamic nucleus sends a small projection to the medial subdivision of the central nucleus and to the basal and lateral nuclei of the amygdala. The lateral preoptic area sends a larger projection to the anterior amygdaloid area, both subdivisions of the central and basal nuclei, and to the lateral and medial nuclei. No degeneration was observed in the amygdala following lesions in the medial preoptic area, the ventromedial nucleus or the lateral hypothalamic area caudal to the anterior hypothalamic area. In a series of animals with lateral preoptic lesions, the site of termination of degenerating boutons on neurons of the amygdaloid nuclei was determined and the course of the degenerative process followed over a period ranging from 2 to 15 days. Many of the boutons, especially in the earlier stages of degeneration, appeared to be of the B3 type, containing flattened vesicles and forming symmetrical synaptic contacts with dendrites or somata. With longer post-operative survival times, however, they became increasingly electron dense and shrunken, so that the bouton type could not be determined.
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    URL: http://dx.doi.org/10.1007/BF00222995
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    Morphology of the gill epithelium of the Lungfish, Lepidosiren paradoxa (1974)
    Springer
    Cell & tissue research 153 (1974), S. 365-381 
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    ISSN: 1432-0878
    Keywords: Gills ; Lepidosiren paradoxa ; Epithelia ; Transport adaptions ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The gills of Lepidosiren are very much reduced, consisting of a few lobe-like filaments. The gill epithelium differs from most other fish in being 4–7 layers thick. Three varieties of cell are described which occur in the inner epithelial layers. It is suggested that these represent stages in the synthesis of a granular secretory product. The superficial cells show characteristics of all 3 cell varieties, the granules apparently being voided into the microvillar pits at the surface. Surface cells are joined by junctional complexes typical of fish epithelia. Epithelial cells are separated by interstitial channels which are bridged by long cytoplasmic processes united by prominent desmosomes. Elongate mucous cells occur in large numbers. The Golgi apparatus is exceptionally large and well defined. It is characterised by accumulation of secretory products at numerous points along the cisternae. Wandering cells containing large granules and 2 types of leucocytes are also present in the interstitial channels. It is suggested that the gill epithelium is involved in active transport; pinocytotic vesicles are present on both sides of the inner epithelial cell layer and the blind interstitial channels are characteristic of transporting epithelia in which steady osmotic gradients operate.
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    URL: http://dx.doi.org/10.1007/BF00229165
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    Effects of preganglionic sympathectomy on secretory changes in parotid acinar cells of rats on eating (1974)
    Springer
    Cell & tissue research 154 (1974), S. 135-150 
    Details
    ISSN: 1432-0878
    Keywords: Parotid glands (Rat) ; Secretion ; Sympathetic ; Autonomic innervation ; Cervical sympathectomy ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rats starved for 40 hours showed similar appearances in both parotid glands despite the fact that cervical sympathectomy had been performed on one side 24 hours before the tissues were removed. The acini of both glands of each animal were loaded with secretory granules and amylase estimations on both sides were similar. Rats starved for 40 hours and then fed chow for 1 1/2–2 1/2 hours showed variable depletion of secretory granules from their parotid acinar cells and corresponding alterations of amylase concentration. There was marked asynchrony in both granule depletion and the phase of resynthesis of individual cells. Rats starved during 40 hours and having had unilateral cervical sympathectomy 24 hours prior to a terminal eating phase of 1 1/2–2 1/2 hours showed big differences between the parotid glands on the different sides of each animal. The sympathectomised gland showed little or no depletion of secretory granules whereas the normally innervated gland showed a variable loss of granules, which was always greater than on the denervated side. Amylase estimations were also lower on the normally innervated side. It is concluded that normal reflex secretion of acinar granules in parotid glands of rats on eating requires intact sympathetic nerve pathways.
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    URL: http://dx.doi.org/10.1007/BF00223160
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    Ultrastructure of the neurosecretory system of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (1974)
    Springer
    Cell & tissue research 154 (1974), S. 289-301 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretory cells ; Leptinotarsa decemlineata ; Innervation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pathways of axonal transport of secretions from neurosecretory cells (NSC) in the medial group (viz. A-, A1, B-, and C-type NSC) and the lateral group (L-type NSC) are described. Individual axons can be recognized in the electron microscope by the kind of neurosecretory particles they contain. In general, the secretions from the medial NSC are carried to the contralateral nervi corporis cardiaci (NCC), those from the lateral NSC to the ipsilateral NCC. Some axons from the A-type NSC, in addition, may run to ipsilateral NCC. All A-type axons have collaterals which run to the ipsilateral NCC. The medial and lateral bundles of “mixed” axons run through one paired NCC but remain separated spatially. Release of secretion from the C-type NSC can take place before the corpus cardiacum is reached. A- and A1-type NSC have additional collaterals that branch from the proximal part of the axons and penetrate deeply into the neuropile of the protocerebral lobes. Local swellings appear to be closely associated with fibers from non-neurosecretory neurons. The sites of contact are characterized by the accumulation of microvesicles (400 Å) near an electron-dense cleft of 150–200 Å width, and resemble regular chemical synapses. The microvesicles prove to be present within the neurosecretory fiber in most of the specimens studied, and within the non-neurosecretory fiber in only a few cases. It seems most likely that the collaterals in some phases convey afferent signals to the NSC which inhibit the release of an efferent neurochemical “messenger” of unknown nature into the neuropile.
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    URL: http://dx.doi.org/10.1007/BF00223727
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    The structure of the nerve fibre layer and neurocord in the enteropneusts (1970)
    Springer
    Cell & tissue research 103 (1970), S. 129-148 
    Details
    ISSN: 1432-0878
    Keywords: Enteropneusts ; Nerve fibre ; Neurocord ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nerve fibre layer and the neurocord of the Enteropneusts Saccoglossus horsti, Harrimania kupfferi and Ptychodera flava have been examined with the electron microscope. The nerve fibres vary in diameter between 0.15 to 10 μm. The majority of the fibres are of the smaller diameters. The nerve fibre layer is intraepidermal, and is divided by processes running radially from the epithelial cells to the basement membrane that separates the nerve fibre layer from the muscle cells. The cells of origin of these nerve fibres are situated mainly in the innermost layers of the epidermal cells. The nerve fibre profiles contain numerous vesicles of very varied diameter and contents, together with larger granular inclusions that are also found in the nerve cell bodies. Morphologically recognisable synapses are rare, but the majority of fibres are in intimate contact with one another. Sometimes the mass of fibres is divided into bundles by the epithelial cell processes. The majority of giant fibres are situated near to the basement membrane of the neurocord. The giant fibres also have a varied content of vesicles as well as neurofilaments and neurotubules. The central canal in Ptychodera flava and the remnants of the central canal in Saccoglossus horsti are both lined by columnar cells that bear microvilli as well as cilia with the typical 9 + 2 pattern of tubules. Scattered amongst these cells are mucus secreting cells which open into the cavity of the canal.
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    URL: http://dx.doi.org/10.1007/BF00335406
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    Über die Struktur der Pilzkörper des Insektenhirns (1970)
    Springer
    Cell & tissue research 103 (1970), S. 365-381 
    Details
    ISSN: 1432-0878
    Keywords: Insects ; Brain ; Corpora pedunculata ; Mushroom bodies ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Die Stiele der Corpora pedunculata im Gehirn von Acheta domesticus L. weisen eine Zonierung auf, die auf einer bestimmten Gruppierung von Globulizellfasertypen in der Stielsäule beruht. 2. Pilzkörperfremde Fasern durchziehen das Stielneuropil in allen Richtungen. Sie sind besonders klar zu erkennen, wenn sie senkrecht zu den Globulizellfasern verlaufen. 3. Sog. chemische Synapsen treten hauptsächlich in der Zone III, die den größten Teil des Stielvolumens einnimmt, und im basalen Stiel in der Zone IV auf. Außer synaptischen Vesikeln, die sich mit Zinkjodid-Osmiumsäure imprägnieren lassen, finden sich in den Pilzkörperfasern zahlreiche osmiophile Grana vom Typ der „dense core vesicles“. 4. Globulizellfasern sind mit pilzkörperfremden Fasern im Stiel synaptisch verknüpft. Sehr wahrscheinlich konvergieren im unteren Stielteil Globulizellfasern auf postsynaptische extrinsische Fortsätze. Wahrscheinlich haben auch Globulizellfasern untereinander synaptischen Kontakt. 5. Synaptische SpezialStrukturen (elektronendichte Auflagerungen, Massierungen von synaptischen Vesikeln) finden sich größtenteils in den anliegenden Winkeln von zwei benachbarten Axonen. Oftmals kann eine Entscheidung über die Polarisierung der Synapsen nicht getroffen werden. 6. Die verschiedenen Fasertypen und ihre Kontakte über Synapsen werden im Hinblick auf die Funktion der Corpora pedunculata diskutiert, die nach verbreiteter Ansicht assoziative Hirnzentren verkörpern.
    Notes: Summary 1. The stalk of the mushroom-bodies (Corpora pedunculata) of the cricket Acheta domesticus L. is composed of nerve fibers from different types of globuli cells. These fibers are arranged into four groups. 2. Extrinsic nerve fibers run through the pedunculus neuropil in different directions. 3. Synapses occur primarily in stalk zone III and in basic stalk parts of zone IV. Intrinsic nerve fibers of globuli cells contain synaptic vesicles, which stain with ZIO-impregnation (Akert and Sandri, 1968), and dense core vesicles. 4. Intrinsic and extrinsic nerve fibers make synaptic contacts. There is some evidence, that globuli cell fibers interact by chemical synapses too. 5. Special synaptic structures such as electron dense projections and accumulations of vesicles are situated predominantly in the angles of two neighbouring axons. The question of synaptic polarization can not always be resolved. 6. The different fiber types and their synaptic contacts are discussed with respect to the function of the corpora pedunculata. The results support the general view, that mushroom bodies represent an important brain center for association.
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    Innervation of iridic melanophores (1970)
    Springer
    Cell & tissue research 105 (1970), S. 538-542 
    Details
    ISSN: 1432-0878
    Keywords: Eye ; Iris ; Melanophores ; Innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nerve supply to the iridic melanophores of the rat was studied with the electron microscope. The adrenergic and cholinergic terminals were identified with the aid of 5-hydroxydopamine, which produces dense-cored 400–800 Å synaptic vesicles in adrenergic axon varicosities, whereas the synaptic vesicles of cholinergic axons remain empty. It was found that both adrenergic and cholinergic terminal axons come in close apposition (200–250 Å) with the melanophores. The appositions have the same appearance as synapses in peripheral tissues. It seems likely that the murine iridic melanophores have a double innervation, although its functional significance is obscure.
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    URL: http://dx.doi.org/10.1007/BF00335427
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    A further contribution to the study of the contact region of Octopus synaptosomes (1970)
    Springer
    Cell & tissue research 103 (1970), S. 48-60 
    Details
    ISSN: 1432-0878
    Keywords: Synaptosomes ; Glutaraldehyde/PTA ; Synapses ; Octopus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Octopus synaptosomes have been examined after glutaraldehyde fixation and phosphotungstic acid (PTA) staining of non-osmicated tissue. The results concentrate on the appearance of the contact region between the presynaptic component of synaptosomes and their postsynaptic processes. Membranes have a triple-layered appearance, consisting of an electronopaque internal coat, an electrontranslucent band and an electronopaque external coat. Good examples of this are found in synaptosomal, dendritic and axonal membranes. At specialized synaptic contact regions the external coats of the pre- and postsynaptic membranes coalesce to form a prominent synaptic plate, which has a width of 18 nm and is subdivided into zones of varying electronopacity. It is suggested that this plate is formed from the specialized external coat of the postsynaptic membrane and the unspecialized external coat of the presynaptic membrane. Presynaptic spicules extend from the internal coat of the presynaptic membrane. They are closely associated with elements of the presynaptic network. It is suggested that the synaptic plate is probably composed of mucopolysaccharides, while the relation of the plate to acetylcholinesterase is discussed. It is proposed that functional localization at the synapse is less precise in octopus than vertebrates.
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    URL: http://dx.doi.org/10.1007/BF00335400
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    Weitere Untersuchungen zur Feinstruktur und Innervation des Pinealorgans von Passer domesticus L. (1970)
    Springer
    Cell & tissue research 105 (1970), S. 276-302 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Passer domesticus ; Synapses ; Nervous pathway ; Sympathetic innervation ; Photo-neuro-endocrine organ
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Im Parenchym der Epiphysis cerebri von Passer domesticus kommen Nervenzellen vor. Ihre Neuriten ziehen im langgestreckten Epiphysenstiel zur Commissura habenularum. Im proximalen Endabschnitt des Epiphysenstiels wird ein Teil dieser Fasern myelinisiert. Zwischen die Nervenfasern schieben sich zahlreiche Pinealocytenausläufer; synaptische Bänder helfen die letzteren eindeutig zu identifizieren. Im Bereich der synaptischen Bänder liegen: 1. 300 Å Vesikel, 2. 300 Å Vesikel und 800–1200 Å Granula, 3. nur 800–1200 Å große granulierte Vesikel. Die Tatsache, daß in Pinealocytenausläufern nebeneinander synaptische Bänder und Granula vorkommen, und daß apikal in zilientragenden Zellen ebenfalls Granula nachweisbar sind, spricht dafür, daß bei Passer domesticus ein Pinealzelltyp sensorische und sekretorische Strukturmerkmale besitzen kann. Außerdem werden Kontaktsynapsen beobachtet; ihre praesynaptischen Fasern enthalten die gleichen Strukturelemente wie die Fasern mit synaptischen Bändern. Die Zahl der Mikrofibrillen und Mikrotubuli variiert in den Pinealocytenausläufern, in den postsynaptischen Dendriten und in den Neuriten so stark, daß es mitunter schwierig ist, diese Fortsatztypen einwandfrei zu unterscheiden und die Zahl der zum Gehirn ziehenden Neuriten exakt zu ermitteln. Efferente sympathische Nervenfasern dringen in die Bindegewebssepten der Epiphyse ein. Sie enthalten Granula mit einem Durchmesser von 300–500 Å und 800–1200 Å. Nach Injektion von Nialamid zeigen beide Granulatypen einen elektronendichten Kern. Mikrospektrographisch ist Serotonin und Noradrenalin in diesen Nervenfasern nachweisbar. Das Material dieser Studie enthält keinen fluoreszenzmikroskopischen oder elektronenmikroskopischen Hinweis darauf, daß die sympathischen Nervenfasern durch die Basalmembran in den Zellverband des Epiphysenparenchyms eintreten. Im elektronenmikroskopischen Bild haben manche Pinealocytenausläufer eine Ähnlichkeit mit autonomen Nervenfasern. Die funktionelle Bedeutung der Vogelepiphyse als photo-neuro-endokrines Organ wird diskutiert.
    Notes: Summary The pineal organ of Passer domesticus contains nerve cells within its parenchyma. Axons of the nerve cells run within the elongated stalk of the pineal organ to the habenular commissure. At the proximal end of the stalk, some axons become myelinated. In the stalk, the axons intermingle with pinealocyte processes containing synaptic ribbons. The synaptic ribbons are in contact with (1) vesicles with a diameter of 300 Å; (2) 300 Å diameter vesicles and 800–1,200 Å diameter dense-core granules; or (3) the dense-core granules only. Dense-core granules are also present in pinealocytes with 9+0 type cilia. These results suggest that sensory and secretory structures are present in the same pineal cell type. Furthermore, “conventional” synapses are present between receptor and nerve cells: The presynaptic fibers have the same structure as the fibers containing synaptic ribbons. The numbers of microfibrils and microtubules vary among postsynaptic fibers (dendrites), the pinealocyte processes, and the neurites. Thus it is difficult to obtain an exact count of the number of axons running to the brain. Efferent sympathetic nerve fibers enter the pineal organ associated with the connective tissue surrounding blood vessels. The fibers show granules of 300–500 Å diameter or 800–1,200 Å diameter. After nialamide injection, both types of granules contain a dense core. Microspectrographically serotonin and noradrenaline are demonstrated in the sympathetic nerve fibers. There is no evidence found in the material of this study to suggest that sympathetic nerve fibers perforate the basement membrane and enter the parenchymal cell complexes of the pineal organ. Pinealocyte processes and sympathetic nerve fibers often show a very similar ultrastructural pattern. The role of the avian pineal organ in photo-neuro-endocrine regulation is discussed.
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    URL: http://dx.doi.org/10.1007/BF00335477
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