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  • Rat  (123)
  • Synapses  (37)
  • Springer  (156)
  • American Chemical Society
  • 1970-1974  (156)
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  • Springer  (156)
  • American Chemical Society
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  • 1
    Electronic Resource
    Electronic Resource
    Rate of normal longitudinal bone growth in the rat (1972)
    Springer
    Calcified tissue international 10 (1972), S. 238-251 
    Details
    ISSN: 1432-0827
    Keywords: Growth ; Bone ; Rat ; Tetracycline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La vitesse de croissance normale en longueur de la métaphyse proximale du tibia est déterminée chez le rat Sprague-Dawley entre les âges de 20 et 100 jours, en utilisant la méthode à la tétracycline. Le taux de croissance ne varie que légèrement dans les groupes d'âges différents. Il est plus élevé chez les animaux jeunes et décroit considérablement en fonction de l'augmentation de l'âge. Les rats mâles présentent une croissance plus élevée que les femelles. Cette étude a pour but de mettre au point une méthode permettant de déterminer les facteurs expérimentaux, liés à la croissance en longueur du rat.
    Abstract: Zusammenfassung Die normale Längenwachstums-Geschwindigkeit der proximalen Wachstumsplatte der Tibia wurde bei Sprague-Dawley-Ratten in einem Alter zwischen 20 und 100 Tagen mittels der Tetracyclinmethode gemessen. Die Wachstumsgeschwindigkeit variierte nur wenig innerhalb der einzelnen Altersgruppen. Die Geschwindigkeit war bei jungen Tieren am höchsten und nahm mit zunehmendem Alter beträchtlich ab. Männliche Ratten wuchsen schneller als weibliche. Diese Arbeit dient als Grundlage, um die experimentelle Beeinflussung des Längenwachstums der Ratte abschätzen zu können.
    Notes: Abstract The rate of normal growth in length from the proximal growth plate of the tibia in the Sprague-Dawley rat was measured between 20 and 100 days of age using the tetracycline method. The growth rate varied only slightly within different age groups. The rate was highest in young animals and decreased considerably with increasing age. Male rats grew faster than female. This study is intended to provide a base for an evaluation of experimental influence on the growth in length of the rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02012553
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  • 2
    Electronic Resource
    Electronic Resource
    The effects of sodium fluoride on bone breaking strength (1974)
    Springer
    Calcified tissue international 14 (1974), S. 283-289 
    Details
    ISSN: 1432-0827
    Keywords: Sodium fluoride ; Osteoporosis ; Bone ; Strength ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'utilisation thérapeutique de fluorure de sodium a été recommandée dans le traitement de diverses maladies osseuses ostéopéniques. Cet emploi est basé principalement sur les effects ostéosclérotiques bien connus du fluorure de sodium, mais on connait mal son effet sur la force de résistance osseuse. L'influence de diverses concentrations de fluorure de sodium sur la force de résistance osseuse de jeunes rats soumis à des régimes riches et pauvres en calcium a été étudiée. L'administration de fluorure de sodium augmente le diamètre osseux, indiquant une stimulation de la formation de l'os périosté, mais la force de résistance osseuse est réduite ou non modifiée par l'ingestion de fluor.
    Abstract: Zusammenfassung Die therapeutische Verwendung von Natriumfluorid ist für eine Anzahl von Knochenmangel-Krankheiten empfohlen worden. Die Empfehlungen basieren hauptsächlich auf den bekannten osteosklerotischen Wirkungen von Natriumfluorid; über dessen Effekt auf die Knochenstärke ist wenig bekannt. In dieser Arbeit wurde der Einfluß verschiedener Konzentrationen von Natriumfluorid auf die Knochenstärken von wachsenden Ratten mit hoher und niederer Calciumeinnahme untersucht. Die Verabreichung von Natriumfluorid erhöhte den Knochendurchmesser, was auf eine Stimulierung der Periostbildung hinwies, die Knochenstärke wurde jedoch durch Fluorideinnahme herabgesetzt oder nicht beeinflußt.
    Notes: Abstract The therapeutic use of sodium fluoride has been recommended in a variety of osteopenic bone diseases. The recommendations are based mainly on the known osteosclerotic effects of sodium fluoride and little information is available as to its effect on bone strength. The influence of various concentrations of sodium fluoride on bone strength in growing rats on high and low calcium diets was studied. The administration of sodium fluoride increased bone diameter, indicating stimulation of periosteal bone formation, but bone strength was reduced or not affected by fluoride ingestion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02060302
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  • 3
    Electronic Resource
    Electronic Resource
    Cell kinetics and morphology of the growth plate in the normal and hypophysectomized rat (1973)
    Springer
    Calcified tissue international 13 (1973), S. 113-129 
    Details
    ISSN: 1432-0827
    Keywords: Kinetics ; Growth ; Epiphyses ; Hypophysectomy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La largeur de la métaphyse tibiale, la zone indifférenciée, la zone sériée et les cellules en dégénerescence ont été observées chez des rats Sprague-Dawley normaux et hypophysectomisés. La production cellulaire de la métaphyse est déterminée sur la base de la croissance osseuse longitudinale déterminée par l'oxytétracycline et la taille des cellules en dégénérescence. La diminution de la croissance osseuse longitudinale, en fonction de l'augmentation de l'âge et après hypophysectomie, est due partiellement, à la diminution de production cellulaire et partiellement à une décroissance de la taille des cellules en dégénérescence dans la métaphyse. L'influence de la production cellulaire et de l'activité mitotique prédomine.
    Abstract: Zusammenfassung Die Breite der proximalen Wachstumsplatte der Tibia, deren undifferenzierter und säulenförmiger Zone und die Größe der nahe bei der Metaphyse auftretenden degenerativen Zellen wurden in normalen und hypophysektomierten Sprague-Dawley-Ratten bestimmt. Die Zellproduktion in der Wachstumsplatte wurde aus dem longitudinalen Knochenwachstum berechnet, welches mittels Oxytetracyclin und der Größe der degenerativen Zellen bestimmt wurde. Es wurde festgestellt, daß die Abnahme des longitudinalen Knochenwachstums bei zunehmendem Alter und nach Hypophysektomie zum Teil einem Rückgang in der Zellproduktion, zum Teil einer Verminderung der Größe der degenerativen Zellen in der Wachstumsplatte zuzuschreiben ist. Der Einfluß der Zellproduktion, und somit der mitotischen Aktivität, herrscht vor.
    Notes: Abstract The width of the proximal growth plate of the tibia, its undifferentiated and columnar zone and the size of the degenerative cell close to the metaphysis, were determined in normal and hypophysectomized Sprague-Dawley rats. The cell production in the growth plate was calculated from the longitudinal bone growth determined with oxytetracycline and the degenerative cell size. It was found that the decrease in longitudinal bone growth with increasing age and after hypophysectomy, is due partly to a decrease in cell production, and partly to a decrease in degenerative cell size in the growth plate. The influence of cell production and thus the mitotic activity predominates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02015402
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  • 4
    Electronic Resource
    Electronic Resource
    Observations on cerebellar granule cells in tissue culture (1970)
    Springer
    Cell & tissue research 107 (1970), S. 454-465 
    Details
    ISSN: 1432-0878
    Keywords: Cerebellum ; Neuron ; Synapses ; Myelin sheath ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In long-term organized cultures of newborn mouse cerebellum, granule cell neurons were studied with silver impregnation and electron microscopy. In silver impregnated cultures, small neurons are defined as granule cell neurons from their size, morphology and location. There are also occasional large nerve endings with the morphology typical of mossy fiber endings. In correlative electron micrographs, granule cell neurons revealed a faithful reproduction of characteristic structures seen in vivo. The fine structural details of cerebellar glomeruli and myelinated granule cell bodies developed in vitro were also described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335434
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  • 5
    Electronic Resource
    Electronic Resource
    Possible axo-axonal synapses between peripheral adrenergic and cholinergic nerve terminals (1970)
    Springer
    Cell & tissue research 107 (1970), S. 508-521 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Axo-axonal ; Adrenergic and cholinergic terminals ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The relations between adrenergic and cholinergic terminals were studied in rat iris and rat heart with the electron microscope. Adrenergic terminals were identified by treating the animals with 5-hydroxydopamine, which produces dense-cored synaptic vesicles in adrenergic terminals in tissues fixed in glutaraldehyde and osmium. The specificity of this observation was verified. It was found that adrenergic and cholinergic nerve terminals often come in close contact with one another, the distance between the adjoining membranes being about 250 Å. At times, faint membrane thickenings could be observed in these places. The available pharmacological, physiological, and morphological evidence leaves little room for doubt that cholinergic terminal fibres can influence the adrenergic fibres. From mainly morphological evidence, it is also postulated that adrenergic terminals influence cholinergic ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335438
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  • 6
    Electronic Resource
    Electronic Resource
    Zwei elektronenmikroskopisch unterscheidbare Formen sekundärer sensorischer Endigungen in einer Muskelspindel der Ratte (1970)
    Springer
    Cell & tissue research 110 (1970), S. 97-107 
    Details
    ISSN: 1432-0878
    Keywords: Muscle Spindles ; Different types of sensory endings ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung In einer Muskelspindel der Ratte, die an einer Serie alternierender Semidünn- und Ultradünnquerschnitte untersucht wurde, wurden zwei benachbart an „nuclear chain“-Fasern gelegene Nervenendformationen unterschiedlicher Bauweise festgestellt. Die beiden Endformationen sind mit ein und derselben Nervenfaser der Gruppe II verbunden und daher als Bestandteile einer sekundären sensorischen Endigung zu betrachten. Die Nervenendformation an einer der beiden „nuclear chain“-Fasern hat anulo-spirale Form. Die Nervenendformation an der anderen „nuclear chain“-Faser weist am Querschnittsbild eine Anzahl von Axonen auf, die zwischen Plasmalemm und Basalmembran der intrafusalen Muskelfaser eng aneinanderliegen. Nicht alle Axonquerschnitte stehen in direktem Kontakt mit der intrafusalen Faser. Das terminale Axon scheint sieh nach Eintritt unter die Basalmembran der intrafusalen Faser mehrfach in relativ dünne Äste unregelmäßigen Verlaufs zu teilen. Diese Form der Endigung könnte ein Korrelat der sog. „flower spray“-Endigung im Sinne Ruffinis (1898) darstellen. Die beiden morphologisch unterschiedlichen Endformationen innerhalb der sekundären Endigung gleichen einander und den Endformationen der primären Endigung bezüglich folgender Ultrastrukturmerkmale: 1. Es besteht synaptischer Kontakt zwischen Axon und intrafusaler Muskelfaser (synaptischer Spalt durchschnittlich 200 Å) ohne Zwischenlagerung von Basalmembranmaterial; 2. die terminalen Axonabschnitte liegen direkt unter der Basalmembran der intrafusalen Muskelfaser und sind nicht von Schwannschen Zellen bedeckt; 3. Mangel an synaptischen Bläschen; 4. desmosomenartige Verhaftungen zwischen Zellmembranen von Axon und intrafusaler Faser; 5. dyadenartige Anlagerungen des sarkoplasmatischen Retikulums an die Zellmembran der intrafusalen Faser im Bereich des synaptischen Spaltes. Nach unseren derzeitigen Vorstellungen sprechen diese Ultrastrukturmerkmale für eine rezeptorische Natur der beschriebenen Nervenendigungen.
    Notes: Summary In a rat muscle spindle transversally cut into a series of alternating semithin and ultrathin sections, two different forms of nerve terminations were found on two neighbouring nuclear chain fibres. The two nerve terminations were connected to the same group II nerve fibre and are consequently constituents of one particular secondary sensory ending. The nerve termination on one of the two nuclear chain fibres is of the anulo-spiral type. The nerve termination on the second nuclear chain fibre shows a number of axons lying closely together between plasma membrane and basement membrane of the intrafusal muscle fibre. Not all of these axons are in direct contact with the intrafusal fibre. The terminating nerve fibre seems to be divided into several branches of rather small diameters and irregular courses. It is suggested that this kind of termination could be a correlate of the so-called “flower spray” type of sensory endings in muscle spindles. The two morphologically different nerve terminations in the secondary ending have the following ultrastructural characteristics in common with those of the primary ending: 1) Synaptic contact between axon and intrafusal muscle fibre (synaptic gap about 200 Å) without interposition of basement membrane material; 2) terminal axons located beneath the basement membrane layer of intrafusal muscle fibres without covering by Schwann cells; 3) lack of synaptic vesicles; 4) desmosome-like structures between plasma membranes of axon and intrafusal muscle fibre, and 5) dyads of the sarcoplasmic reticulum adjacent to the synaptic cleft. According to present knowledge these features indicate that all of these endings are sensory ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343988
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  • 7
    Electronic Resource
    Electronic Resource
    Über neuritenähnliche intraventrikuläre Fortsätze und ihre Kontakte mit dem Ependym der Seitenventrikel der Katze (1970)
    Springer
    Cell & tissue research 111 (1970), S. 572-585 
    Details
    ISSN: 1432-0878
    Keywords: Brain ; Intraventricular cellular processes ; Ependyma ; Lateral ventricle ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Ependym und subependymale Strukturen der Seitenventrikel von Katzen aus dem Bereich des Nucleus caudatus und des Corpus callosum wurden nach Perfusionsfixierung elektronenmikroskopisch untersucht. Dort findet sich eine Reihe von Neuritenanschnitten, deren kolbenförmige Auftreibungen leere Vesikel, “dense core granula” und Mitochondrien enthalten. Neben diesen neuronalen Elementen werden auch Zellfortsätze nichtneuronaler Natur im Ventrikellumen beobachtet, die Ependym- und intraventrikulären Zellen entstammen. An umschriebenen Stellen nehmen diese kolbig aufgetriebenen Fortsätze desmosomenartige Kontakte mit dem Ependym auf. An diesen Orten umgeben Mikrovilli die Fortsätze korbartig. Ob es sich bei diesen Kontakten um synapsenartige Strukturen handelt, oder um „Rezeptoren“ für unbekannte chemische Stoffe, wird diskutiert. Die Kontakte sind unabhängig von der Form der Ependymzellen und davon, ob diesen graue oder weiße Substanz unterliegt. Zwischen und in den Ependymzellen finden sich — bedingt durch den unterschiedlichen Gehalt an Zellorganellen — drei verschiedene Arten von Fortsätzen. Die Zahl der neuronalen Fortsätze in diesem Bereich ist sehr viel kleiner als im Ventrikellumen.
    Notes: Summary Ependyma and subependymal regions of the lateral ventricles of cats (area of Nucleus caudatus and Corpus callosum) were fixed by perfusion and investigated electronmicroscopically. Intraventricular axons showing a beaded shape with smaller and thicker parts were found. The varicosities contain empty vesicles, dense core granules and mitochondria. Beside those certainly neuronal elements there exist intraventricular cell processes originating from ependymal cells and free cells. The neuronal processes make desmosome-like contacts with the ependyma. These regions of contact are surrounded by basket-like arranged microvilli. It is discussed, whether the contacts function like synapses or as receptors for a substance, which is still unknown. Contacts do not depend on the shape of ependymal cells. They exist with the ependyma of Nucleus caudatus (grey substance) as well as with the ependyma of Corpus callosum (white substance). Because of the different contents of cell-organelles one can differentiate three different sorts of processes situated inter- or intracellularly in the ependyma. Neuronal processes within the lateral ventricles are more numerous than those found within the ependymal layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330933
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  • 8
    Electronic Resource
    Electronic Resource
    The postnatal development of the synapse: A morphological approach utilizing synaptosomes (1970)
    Springer
    Cell & tissue research 111 (1970), S. 179-194 
    Details
    ISSN: 1432-0878
    Keywords: Synaptosomes ; Rat cerebral cortex ; Synapses ; Postnatal development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synaptosomes (nerve-ending particles) prepared from the cerebral cortex of rats, aged 2–21 days, were examined after fixation in glutaraldehyde and osmium tetroxide, in order to study the development of the contact region between their pre- and postsynaptic components. Synaptosomes were present at all ages studied, although they increased in number and underwent morphological changes, e.g. a decrease in ribosomes and increase in synaptic vesicles, during development. The seventh postnatal day appeared to be a critical period for development, as many adult features were first observed at this time. The synaptic contact region was characterized by desmosome-like symmetrical thickenings until the fourth postnatal day, after which it became increasingly asymmetrical. The postsynaptic thickening, which had been undifferentiated until the seventh day, underwent a focalization of its material at this stage to form postsynaptic densities typical of the adult synapse. Cleft material was present at all ages, although for the first few days it was sparse and comparatively unorganized. An attempt has been made to distinguish between synaptosomes derived from axosomatic and axodendritic endings. The possible significance of the early desmosome-like thickenings is discussed, and the role of the cleft material and post-synaptic densities in the development of the synapse is analysed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00339784
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  • 9
    Electronic Resource
    Electronic Resource
    Spine-like astrocytic protrusions into large axon terminals (1971)
    Springer
    Cell & tissue research 115 (1971), S. 494-500 
    Details
    ISSN: 1432-0878
    Keywords: Axon ; Synapses ; Astrocytes ; Thalamus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopic studies and three-dimensional graphic reconstructions from serial sections have shown that the large axon terminals of synaptic glomeruli in the ventrobasal nucleus of the rat are invaginated by spine-like protrusions from the astrocyte processes surrounding the glomeruli (“micro-trophospongium”). The astrocytic protrusions are similar in dimensions and internal morphology to the synapse-bearing dendritic excrescences that also invaginate the large axon terminals. Consequently astrocytic protrusions may be overlooked, or confused with dendritic excrescences sectioned at a non-synaptic level. The intimate neuronal—neuroglial relationship at such large axon terminals may reflect ion-exchange or metabolic interactions between the astrocytes and the axon terminal.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335715
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  • 10
    Electronic Resource
    Electronic Resource
    On the innervation of the rat and pig adrenal cortex (1971)
    Springer
    Cell & tissue research 116 (1971), S. 151-156 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Innervation ; Receptors ; Rat ; Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the adrenal cortex of the rat and the pig is investigated with the electron microscope. Nerve fibers containing synaptic and two types of dense-cored vesicles come into contact with endocrine cells. There are no specialized pre- and postsynaptic membranes. The synaptic cleft is about 200 Å wide. Generally the basement membrane between nerve and cell is absent. These observations are discussed on the base of more recent experimental findings. Small fibers having an average diameter of about 0.2 to 0.5 μ and containing only tubules and filaments are considered to represent parts of an afferent nervous system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00332863
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  • 11
    Electronic Resource
    Electronic Resource
    Histochemical and chemical studies on pre- and postnatal development of the different systems of “short” and “long” adrenergic neurons in peripheral organs of the rat (1971)
    Springer
    Cell & tissue research 116 (1971), S. 319-341 
    Details
    ISSN: 1432-0878
    Keywords: Adrenergic neurons ; “Short” and “long” systems ; Pre- and postnatal development ; Peripheral organs ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adrenergic innervation in the submaxillary gland, heart, kidney, small intestine, and accessory male genital organs and the development of the adrenal chromaffin cells and the sympathetic ganglia were studied in the rat from 15 days post coitum to 16 days post partum using the fluorescence histochemical method of Falck and Hillarp. The postnatal development of the noradrenaline concentrations in the heart and vas deferens was followed by fluorometric determinations. At about 15 days post coitum, the anlagen of the sympathetic chains were well visible in the form of two dorsal segmented columns of small branching sympathicoblasts exhibiting an intense catecholamine fluorescence. In the midline, ventrally to these two anlagen, another column of sympathicoblasts developed; this seemed to give rise to the prevertebral ganglia and to the short adrenergic neurons supplying the internal genital organs. At the level of the adrenal anlagen, small intensely fluorescent chromaffin cells were collected in two bilateral groups which became enclosed by adreno-cortical cells. This enclosure was, however, not complete even at two weeks post partum. Bundles of growing sympathetic nerves were visible in the periphery of the various organs studied at 19–21 days post coitum. A terminal innervation of the organs suggestive of a functional transmitter mechanism did not start to establish until at or immediately after birth. The final pattern of innervation was usually reached at about one week post partum, and the following development proceeded largely in the form of a quantitative increase in the number of nerves participating in the innervation apparatus. The adult level of noradrenaline in the heart and vas deferens was reached three to five weeks after birth. The small intestine was an exception in that the final pattern of innervation in the wall was attained immediately after birth. There was no overt difference in the rate of development of the terminal sympathetic innervation in organs supplied by short adrenergic neurons (accessory male genital organs) compared to the innervation of the submaxillary gland, heart and kidney, which receive classical long adrenergic neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330631
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  • 12
    Electronic Resource
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    The fine structure of the granulosa cells in the domestic fowl and the rat (1971)
    Springer
    Cell & tissue research 119 (1971), S. 58-67 
    Details
    ISSN: 1432-0878
    Keywords: Ovary ; Rat ; Fowl ; Granulosa cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The granulosa cells of the ovarian follicle of the rat and the domestic fowl have been studied with the light and electron microscope. The nuclei of the granulosa cells were irregular with indentations and large in proportion to the cytoplasm of the cell. The mitochondria had a dense, dark matrix with only few cristac. The Golgi apparatus was moderately developed, located towards the oocyte in a juxtanuclear position. The endoplasmic reticulum was rather sparse. Lipid droplets were only occasionally encountered. Microtubules were regularly observed. The functions of the granulosa cells are discussed. Compared with the steroid-producing cells of the theca interna of the same follicles, the granulosa cells primarily are the nursing cells for the growing oocyte and mainly have the characteristics of protein forming cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00330538
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  • 13
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    Ultrastructural studies on the hypothalamic neurosecretory neurones of the rat (1971)
    Springer
    Cell & tissue research 122 (1971), S. 283-300 
    Details
    ISSN: 1432-0878
    Keywords: Paraventricular nucleus ; Rat ; Synthesis of hormones ; Acid phosphatase ; Osmium impregnation ; Neurosecretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural features of the paraventricular neurones of the non-treated rat are presented comparing them with those of the supraoptic neurones. No striking differences are seen between the general electron microscopic characteristics of the paraventricular and supraoptic neurones. The importance of adequate fixation to obtain good preservation of the neurones is emphasized, since inadequate fixation can cause e.g. artefactual appearance of “dark neurones”. The previously presented classification of the neurosecretory neurones into two categories (e.g. “light and dark neurones”) on the basis of the number of ribosomes is not considered justifiable, since their number can vary to a very great extent even within a single cell. The synthesis of neurosecretory products in the paraventricular neurones obviously follows the general mode of the synthesis of secretory proteins: ribosomes—RER—Golgi complex—secretory vesicles. On the basis of the localization of heavy metal deposits after osmium impregnation and demonstration of acid phosphatase the Golgi complex of the paraventricular neurones is found to be polarized. The direction of the polarity is discussed. The substructures of the dense cores of the neurosecretory granules and of the contents of the lysosomal dense bodies are nearly identical. Therefore it is considered impossible to determine positively the nature of the dark condensed material within the Golgi complex. The characteristics of the immature neurosecretory granules and the possibility of releasing neurosecretory products into the cytoplasm already within the perikarya are speculated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00935990
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  • 14
    Electronic Resource
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    A two-filament system and interaction of heavy meromyosin (HMM) with thin filaments in smooth muscle (1971)
    Springer
    Cell & tissue research 122 (1971), S. 350-356 
    Details
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Two-filament system ; Small intestine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of glycerinated smooth muscle from small intestine of adult rat was investigated by electron microscopy. In the central parts of the tissue blocks a two-filament system was found, consisting of parallel thick and thin filaments with regularly spaced interconnections, closely resembling that of striated muscle. In the peripheral parts of the blocks only thin filaments were found. The thin filaments were identified as actin by the formation of arrowhead complexes after incubation with heavy meromyosin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00935994
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  • 15
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    Identification of helical polyribosomes in sections of mature skeletal muscle fibers (1971)
    Springer
    Cell & tissue research 121 (1971), S. 531-547 
    Details
    ISSN: 1432-0878
    Keywords: Helical polyribosomes ; Skeletal muscle ; Polysomes ; Levator ani ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The localization and configurations of ribosomes in mature white skeletal muscle fibers of the rat were investigated. Differential visualization of ribosomes and glycogen granules was obtained by fixation with glutaraldehyde only and staining of the sections with uranyl acetate. Ribosomes are then electron dense and glycogen granules electron transparent. Their identity was ascertained by selective extractions of ribonucleic acid and polysaccharide. The vast majority of the ribosomes is not membrane-bound. They are located intermyofibrillarly (predominantly at the level of the I-bands), beneath the sarcolemma, and in the paranuclear cones of sarcoplasm. Occasionally short stretches of granular reticulum occur, often as characteristic double walled vesicles with ribosomes on the inner membrane only. Three main types of polysomal configurations are observed: rosettes of 4 to 6 ribosomes, helical arrays, and whorls of up to about 25 probably membrane-bound ribosomes. The average number of ribosomes in the extended helical configurations is estimated to be about 60. It is argued that these helices represent the polysomes instrumental in the synthesis of the large subunits of myosin. It is emphasized that helical polyribosomes are by no means typical of striated muscle, but probably represent a common configuration of large free polysomes.
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    URL: http://dx.doi.org/10.1007/BF00560158
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    Immersion and perfusion fixed rat adrenal medulla: The problem of mixed cells, clear cells, and the mode of secretion (1972)
    Springer
    Cell & tissue research 126 (1972), S. 261-277 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal medulla ; Rat ; Cell types ; Secretion ; Influence of fixation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Nebennierenmark der Ratte wurde nach Anwendung verschiedener Fixationsmethoden untersucht. Nach Immersionsfixation mit Glutaraldehyd oder Osmiumtetroxyd finden sich in der Nebenniere sog. Mischzellen, helle Zellen, syncytiale oder plasmodiale Zellen, die von den Untersuchern als Artefaktbildungen angesehen werden. In allen Proben nach Perfusionsfixation wurden solche Artefaktbildungen niemals beobachtet. Bei Immersionsfixation wurde eine enge Beziehung zwischen Sekretgranula und Cytoplasmamembran beobachtet, was bei Perfusionsfixation selten der Fall war. Die heutigen Theorien über den Sekretionsmechanismus bei Nebennierenmarkzellen werden aufgrund der vorgelegten Ergebnisse diskutiert. Die Arbeit zeigt die wesentlichen Vorteile der Anwendung der Perfusionsfixation für die Untersuchung der Nebenniere.
    Notes: Summary The adrenal medulla of the rat was studied utilizing various methods of fixation. In adrenal medulla specimens after immersion fixation either with glutaraldehyde or osmium tetroxide, elements such as mixed, clear, syncytial, or plasmodial cells, believed to be of artifactual origin, are observed in all of this material examined. These elements are absent in the specimens prepared by perfusion fixation. In specimens prepared by immersion fixation, secretory granules are found in close proximity to the plasma membrane; this localization is infrequent after perfusion fixation. Current theories of the mechanism of secretion of adrenal medullary hormones are discussed on the basis of our results. This investigation demonstrates the advantage and necessity of perfusion fixation in the study of the adrenal medulla.
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    URL: http://dx.doi.org/10.1007/BF00307220
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    The fine structure of macrophages in the enamel organ, with special reference to the microtubular system (1972)
    Springer
    Cell & tissue research 126 (1972), S. 466-482 
    Details
    ISSN: 1432-0878
    Keywords: Macrophages ; Microtubules ; Enamel organ ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the enamel organ of rat incisors macrophages are present in the zone of matrix formation, the transitional zone, the enamel maturation and pigmentation zone. The macrophages accumulate adjacent to redifferentiating amelocytes in the transitional zone. The macrophages phagocytize fragments of disintegrating amelocytes. In addition to the well known complement of organelles the macrophages present an elaborated microtubular system, scattered, thick filaments, a cortical feltwork of thin filaments, and spherical nuclear bodies. The microtubules emanate from “attached” and free pericentriolar satellites and radiate aster-like towards the cell surface or into pseudopods or curve along the nuclear surface for long distances, often related to nuclear constrictions. It is suggested that the microtubular system plays a prominent role in directional movement of the macrophages. The cortical filaments, if contractile, may create the cytoplasmic flow necessary for the cell motility.
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    URL: http://dx.doi.org/10.1007/BF00306907
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    Über die Struktur der Pilzkörper des Insektenhirns (1972)
    Springer
    Cell & tissue research 127 (1972), S. 240-257 
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    ISSN: 1432-0878
    Keywords: Insects ; Brain ; Corpora pedunculata ; α-lobe ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Organisation der α-Loben der Pilzkörper im Gehirn von Acheta domesticus L. wird nach licht- und elektronenmikroskopischen Befunden beschrieben. Der säulenartige Faserkomplex des α-Lobus besteht aus Fortsätzen von Pilzkörperzellfasern (intrinsischen Fasern, IF) und pilzkörperfremden Fasern (extrinsischen Fasern, EF), die in den Lobus eindringen. Die feinen IF durchziehen den Lobus hauptsächlich parallel zu seiner Längsachse, während die EF zumeist senkrecht zur Längsachse angeordnet sind. Der Lobus erscheint von seiner Peripherie bis zu seinem Zentrum durch IF-Zonen gegliedert. Die Verteilung der EF weist auf eine zusätzliche Ordnung von der Basis zur Spitze des Lobus hin. Zahlreiche polarisierte Synapsen verbinden IF mit EF. Die IF zeigen Vesikelanhäufungen und präsynaptische Apparate besonders in Erweiterungen, die auch in Golgi-Präparaten lichtmikroskopisch zu sehen sind. Es werden zwei EF-Typen unterschieden: 1. Postsynaptische EF (zahlreich) und 2. EF mit prä- und postsynaptischen Kontakten, die nur in einigen Regionen des α-Lobus gefunden wurden. Präsynaptische IF konvergieren auf „dendritische“ EF, die Verbindungen mit anderen Teilen des Hirns und des Nervensystems herstellen. Funktionelle Gesichtspunkte werden diskutiert.
    Notes: Summary The organization of the α-lobes of the corpora pedunculata in the brain of the cricket Acheta domesticus L. has been investigated in the light and electron microscopes. The cylindrical fibre complex is composed of branches of “mushroom-body” fibres (intrinsic fibres) and extrinsic fibres, which penetrate the α-lobe. Intrinsic fibres (IF) run through the α-lobe in the same direction, but not strictly parallel to each other or to the axis of the α-lobe. Extrinsic fibres (EF) and their fine branches are often arranged perpendicular to the axis of the α-lobe. There is some evidence that different IF zones occur in the α-lobe when passing from its periphery to its centre. The distribution of EF may reflect a structural order when passing from the base of the lobe to its top. Numerous polarized synapses connect the IF with the EF. The IF show clusters of vesicles and presynaptic figures especially in their “blebs”, which can be seen in Golgi preparations for light microscopy. Two types of EF are distinguished on the basis of their synaptic junctions: (1) postsynaptic EF (abundant) and (2) EF with pre- and postsynaptic sites (perhaps restricted to some regions of the α-lobe). Presynaptic IF converge on EF, which may transfer excitation from the α-lobe to different parts of the brain and nervous system.
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    URL: http://dx.doi.org/10.1007/BF00306806
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    An electron microscopic study of the normal synaptic relationships and early degenerative changes in the rat olfactory tubercle (1972)
    Springer
    Cell & tissue research 127 (1972), S. 462-482 
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    ISSN: 1432-0878
    Keywords: Olfactory tubercle ; Rat ; Degeneration ; Synapse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The olfactory tubercle of the rat was studied by electron microscopy both in the normal and after ipsilateral olfactory bulb ablation at survival times of from 14 hours to seven days. Particular emphasis was placed on synaptic structures and their changes following the lesion. Normal synapses are similar to those described in previous studies and presynaptic profiles are of at least three types. Types-A and -B contain round vesicles and form asymmetrical contacts and type-C profiles contain flattened vesicles and form symmetrical contacts. There appear to be two major types of degenerative changes. The electron-lucent type predominates at early survival times and is seen first at 14 hours. These profiles show an early reduction in numbers of vesicles with mitochondrial swelling followed by shrinkage of the profile. These profiles become increasingly electron-dense at later survival times. The second major type of degenerating profile is initially electron-dense. The earliest changes in these profiles are an increased axoplasmic density and increased microtubular density and clumping without apparent loss of vesicles. These profiles also become progressively more electron-dense at longer survival times. The observations are discussed in relation to previous reports.
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    URL: http://dx.doi.org/10.1007/BF00306866
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    Synapses of crayfish abdominal ganglia with special attention to afferent and efferent connections of the lateral giant fibers (1972)
    Springer
    Cell & tissue research 127 (1972), S. 526-544 
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    ISSN: 1432-0878
    Keywords: Synapses ; Crustacea ; Abdominal Ganglia ; Lateral glant fibers ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The abdominal ganglia of the crayfish Astacus pallipes contain numerous vertebrate-like synapses which are characterized by presynaptic vesicles, darkened pre- and post-synaptic membranes, cleft material, and post-synaptic “fuzz”. Such synapses occur throughout the ganglia but are most easily found dorsally, where the neuropile is relatively coarse. The neuropile is far from homogeneous. Regional variations in fiber size, in degree of profile tortuosity, and in kind, magnitude, and distribution of vesicular content result in conspicuous textural variations. The structural polarity of synapses between the lateral giant fibers and other neurons is consistent with known physiological polarity and, hence, validates our criteria for recognition of synapses within the ganglion.
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    URL: http://dx.doi.org/10.1007/BF00306869
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    Intercellular bridges and division patterns of rat spermatogonia (1972)
    Springer
    Cell & tissue research 127 (1972), S. 201-208 
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    ISSN: 1432-0878
    Keywords: Spermatogenesis ; Rat ; Mitosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pattern of intercellular cytoplasmic bridges between rat spermatogonia and between spermatocytes is illustrated from electron microscopy of serial sections. Clones, or syncytia, containing as many as 22 connected spermatogonia and as many as 74 connected spermatocytes were observed. The absence of closed rings of cells agrees with the observation that intercellular bridges are the result of incomplete cell division, rather than cell fusion. The bridges thus are a record of spermatogonial divisions within a clone. In early spermatogonial generations there is a predominantly linear arrangement. The groups of spermatocytes have more side branches. From the presence of synaptonemal complexes it is concluded that the connected spermatocytes of a given clone are in about the same developmental stage. The pattern of intercellular bridges indicates, however, that not all nuclei in a clone undergo mitosis in the same cycle. The connected cells of a clone are therefore not all of the same generation. From unconnected bridges it is assumed that new clones originate from single cells or groups of spermatogonia which separate from an existing clone.
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    URL: http://dx.doi.org/10.1007/BF00306802
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    Contractility and structure of adult rat seminiferous tubules in organ culture (1972)
    Springer
    Cell & tissue research 130 (1972), S. 171-179 
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    ISSN: 1432-0878
    Keywords: Tubuli seminiferi ; Rat ; Structure ; Contractility ; Organ culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Isolated pieces of seminiferous tubules of adult rats were grown in organ culture for up to 8 weeks in Petri dishes on the surface of nutrient agar. The medium consisted of newborn calf serum, Eagle's minimum essential medium, glutamate and antibiotics. This method allowed observation of the contractions of the seminiferous tubules in the culture. Contractility, light and electron microscopic structure and histochemically demonstrable activities of alkaline phosphatase and ATPase of the tubule walls were studied at 1-week intervals. The contractility and alkaline phosphatase activity were maintained in the tubule wall for 3 weeks, and the activity of ATPase was maintained for 5 weeks. The thin filaments of the myoid cells, which are responsible for the contractility, were seen with the electron microscope in tubules cultured for 5 weeks. The organ culture method described in the present paper seems to be valuable for studies concerning the functioning of the myoid cells of the seminiferous tubules and the possibility that this is regulated by hormones.
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    URL: http://dx.doi.org/10.1007/BF00306955
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    Ultrastructural evidence for exocytosis in the median eminence of the rat (1972)
    Springer
    Cell & tissue research 131 (1972), S. 99-107 
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    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Exocytosis ; Micro-pinocytosis ; Releasing factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Exocytosis has been demonstrated by electron microscopy in the external zone of the median eminence of the rat. Exocytotic profiles have been observed in nerve fibres characterized by the presence of granular vesicles with median diameters of 90–103 nm and agranular vesicles of about 50 nm. In addition to the small agranular vesicles, coated vesicles of the same size have been found in many nerve fibres, suggesting that at least part of the agranular vesicles in the median eminence originate by micro-pinocytosis. The nature of the fibres showing exocytosis is discussed. Attention is drawn to the possibility of identifying types of fibres in the median eminence by the occurrence of exocytosis.
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    URL: http://dx.doi.org/10.1007/BF00307203
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    Form und Verteilung subependymaler Basalmembranlabyrinthe am Ventrikelsystem der Ratte (1972)
    Springer
    Cell & tissue research 132 (1972), S. 553-562 
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    ISSN: 1432-0878
    Keywords: Basement membrane ; Brain ventricles ; Rat ; Subependymal labyrinths ; Light- and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Mit der Perjodsäure-Bisulfit-Aldehydthionin-Färbung (Specht) lassen sich am ganzen Ventrikelsystem des Rattengehirns sub- und interependymale Strukturen lichtmikroskopisch nachweisen, die elektronenmikroskopisch als Basalmembranlabyrinthe (BML) identifiziert werden können. Verschiedene Formen dieser BML lassen sich unterscheiden. Sie stehen in Verbindung mit subependymalen Kapillaren. Die Verteilung der BML wird in Ventrikelkarten dokumentiert.
    Notes: Summary Sub- und interependymal structures, being demonstrable by a period-acid-bisulfit-aldehydthionine-method (Specht), occur in the whole ventricular system by light microscopy. They can be identified electron microscopically as basement membrane labyrinths (BML). Different shapes of these BML can be distinguished. They are in communication with the basement membrane of subependymal capillaries. The distribution of BML is documented in “ventricular maps”.
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    URL: http://dx.doi.org/10.1007/BF00306641
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    Ultrastructural studies on the hypothalamic neurosecretory neurons of the rat (1972)
    Springer
    Cell & tissue research 134 (1972), S. 205-225 
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    ISSN: 1432-0878
    Keywords: Diabetes insipidus ; Rat ; Hypothalamo-neurohypophysial system ; Synthesis of hormones ; Light- and Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The general ultrastructural features of the hypothalamo-neurohypophysial system in rats with hereditary hypothalamic diabetes insipidus (DI-rats, Brattleboro strain) are described. There is no decisively distinguishing difference between the neurons of the supraoptic and paraventricular nuclei. The neurons of both nuclei show signs of active protein synthesis. The perikarya of the neurons are markedly hypertrophic, the nuclei are large and the nucleoli prominent. In the cytoplasm there are numerous ribosomes, abundant rough-surfaced endoplasmic reticulum and extensive Golgi complexes. However, very few neurosecretory granules are to be seen. The axons of the hypothalamo-neurohypophysial tract are likewise enlarged and the paucity of neurosecretory granules is a striking feature also in the area of the tract. The majority of nerve endings in the posterior pituitary of DI-rats are devoid of neurosecretory granules. Microvesicles are abundant in the nerve endings and there are findings which suggest that microvesicles are involved either in endoor exocytosis. The signs of active protein synthesis and the concomitant paucity of neurosecretory granules are interpreted to imply transportation of the secretory proteins in an extragranular phase. The possible mode of release of the secretory proteins from the nerve endings and the role of microvesicles therein are discussed.
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    URL: http://dx.doi.org/10.1007/BF00307154
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    On the fine structure of the perivascular cells in the neural lobe of rats (1972)
    Springer
    Cell & tissue research 132 (1972), S. 25-34 
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    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Perivascular cells ; Neurosecretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The purpose of this study is to investigate the ultrastructural features of perivascular cells as found in the neural lobe of the hypophysis. In particular, an inquiry was made into the nature of the relationship of such cells to neurosecretory fibers and endings. The latter, in fact, are often invaginated within the perivascular cells and enveloped by their processes; furthermore, they often reveal a certain number of empty granules as well as characteristics of degenerative nature. In the course of this study the localization of the perivascular cells has been investigated as well as that of their processes within the extensive interlobular network typical of the hypophysial neural lobe of rodents. Based on the data gathered, the hypothesis is put forward that the perivascular cells play an important role in the turnover of neurosecretory endings, both under physiological and experimental conditions, contributing thereby to the release of post-hypophysial hormones.
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    URL: http://dx.doi.org/10.1007/BF00310294
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    Elektronenmikroskopische Untersuchungen zur funktionellen Morphologie des Tubero-hypophysären Systems der Ratte (1973)
    Springer
    Cell & tissue research 139 (1973), S. 101-148 
    Details
    ISSN: 1432-0878
    Keywords: Infundibulum ; Rat ; Neuro-glial synapses ; Neuro-Vascular contacts ; Corticotropin-Releasing Factor ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Die Gefäßfortsätze von ependymalen und subependymalen Zellen bilden in der subependymalen Zone und in der Zona interna des Ratteninfundibulum mit Nervenfasern kompakte neuro-gliöse Faserbündel, die sich in der Zona externa aufzweigen. 2. In allen Zonen des Infundibulum kommen zwischen den Nervenfasern und den Gefäßfortsätzen zahlreiche neuro-gliöse Synapsen vor. In den Gefäßfortsätzen fällt die hohe Zahl an Mikrotubuli sowie die zahlreichen, vielgestaltigen Einschlüsse auf. 3. In der subependymalen Zone sind die Interzellularspalten an bestimmten Stellen außerordentlich weit. Sie haben eine kanalartige Beschaffenheit und enthalten feine Bündel von Nervenfasern. 4. Von den lateralen Anteilen des Infundibulum her erreichen Dendriten von Ganglienzellen des Nucleus infundibularis die Mitte des Infundibulum. In dieser Region sind axodendritische Synapsen anzutreffen. 5. Morphometrische Analysen der Nervenfaserendigungen der Zona externa von Normaltieren zeigen, daß die prozentuale Verteilung der nach Granulagröße differenzierten Nervenfaserklassen für Mitte und Seite der Zona externa etwa gleich ist. Zwischen der Größe der Elementargranula und der Anschnittfläche der zugehörigen Nervenfasern besteht eine direkte Beziehung. 6. Die Nervenfaserendigungen erreichen die Basalmembran des perikapillären Raumes fast ausschließlich im Bereich von gefäßwärts gerichteten Vorwölbungen der Zona externa. Das Ausmaß, in dem Nervenfasern im Vergleich zu den Gefäßfortsätzen von Ependymund Gliazellen den perivaskulären Raum erreichen, ist medial weitaus größer als lateral. 7. Bei bilateral adrenalektomierten Ratten nimmt in bestimmten, vorwiegend lateral gelegenen Nervenfasern die Zahl und Größe der Elementargranula in Abhängigkeit von der Überlebensdauer zu. Dies dürfte auf eine verstärkte Synthese und Speicherung von Corticotropin-Releasing Factor in diesen Nervenfasern zurückzuführen sein. Gegenüber dem Normalbefund ist die neurohämale Kontaktfläche erheblich vergrößert. Der perivaskuläre Raum enthält zerfallene Nervenfaserteile, die durch Bindegewebszellen phagocytiert werden. Diese Veränderungen dürften durch eine unter Versuchsbedingungen verstärkte Wachstumstendenz der Nervenfasern in Richtung auf die Blutgefäße und durch eine Abschnürung der Nerven-faserendigungen ausgelöst werden.
    Notes: Summary 1. In the subependymal and internal zones of the rat median eminence nerve fibres and vascular processes of ependymal and subependymal cells form neuro-glial bundles. They branch in the external zone. 2. In all these three zones of the infundibulum numerous neuro-glial synapses are found between nerve fibres and vascular processes of glial cells. The vascular processes contain a high number of microtubules as well as polymorphous granular inclusions. 3. In certain regions of the subependymal layer the intercellular spaces are enlarged. They form channel-like spaces containing small bundles of delicate nerve fibres. 4. Nerve cells of the infundibular nucleus located in the lateral parts of the infundibulum send dendrites to the medial parts of the infundibulum. In this area axo-dendritic synapses are found. 5. For morphometric analysis, the nerve fibres of the external zone were classified according to the diameter of their granules. It is shown that in the different regions of the external zone the distribution of the various types of nerve fibre is similar. Moreover it can be seen that a direct correlation exists between the size of the sectional plane of a given nerve fibre and the size of the granules it comprises. 6. Nerve fibre endings abutting on the basement membrane of the pericapillary space are mostly found in bulb-like protrusions of the external zone. The extent to which nerve fibres reach the perivascular space—as compared with the vascular processes of ependymal and glial cells—is higher in the medial than in the lateral parts of the infundibulum. 7. In bilaterally adrenalectomized rats the number and diameter of elementary granules increases in nerve fibres located laterally. This increase is directly related to the survival time and may be due to an enhanced synthesis and storage of Corticotropin-Releasing Factor in these nerve fibres. Compared with the findings in untreated animals the neurohemal contact area is significantly enlarged. The perivascular space contains degenerating nerve fibres which are undergoing phagocytosis by connective tissue cells. It is assumed that these alterations are due to the increased growth of nerve fibres towards the vessels of the “Mantelplexus”, and that, following adrenalectomy, this excessive growth leads to a pinching off of nerve fibres.
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    The adrenergic innervation of the renal artery and vein of the rat (1973)
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    Cell & tissue research 138 (1973), S. 261-272 
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    ISSN: 1432-0878
    Keywords: Extrarenal blood vessels ; Rat ; Adrenergic nerves ; Fluorescence microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adrenergic innervation of the extrarenal blood vessels of the rat left kidney was investigated by fluorescence histochemistry and by electron microscopy. The trunk of the renal artery proximal to the aorta is elastic and appears to be very sparsely innervated. In contrast, near the kidney the renal artery—which divides into 3 to 4 large branches of the muscular type possesses a dense adrenergic innervation. The adrenergic terminal axons are situated in the adventitia close to the external elastic lamella, but only rarely in close contact with smooth muscle cells. In most instances several terminal axons are grouped and enclosed by a Schwann cell, single axons being rare. All terminal axons are able to take up and to store 5-hydroxydopamine which strongly suggests that they are adrenergic. The innervation of the renal vein is more sparse than that of the muscular arteries but somewhat denser than that of the elastic artery. In addition, close to the origin of the renal artery the presence of “small intensively fluorescent” (SIF) cells as well as of some adrenergic ganglion cells is noted. The latter are situated in the adrenergic nonterminal axon bundles, which run parallel to the blood vessels. It is concluded that the uneven adrenergic innervation along the artery as well as individual variations in the branching of the artery are the main causes of the unusually high individual variations of the NA content of this organ such as used in pharmacological experiments.
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    URL: http://dx.doi.org/10.1007/BF00306611
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    Modifications des cellules gonadotropes de la préhypophyse chez la ratte injectée de testostérone au cours du cycle oestral (1973)
    Springer
    Cell & tissue research 138 (1973), S. 63-73 
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    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Rat ; Gonadotrophic cells ; Cycle, influence of testosterone ; Light microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 4-day cyclic adult female Wistar rats were injected subcutaneously with testosterone propionate on diestrus 1 at 16:00 and on diestrus 2 at 10:00 respectively. Non-injected females served as controls. Autopsy was performed on diestrus 2 at 23:00, and on proestrus at 14:00 and 17:00 respectively. The blue Alcian-PAS staining was used to evidence FSH (β) and LH (γ) pituitary cells. In control animals and in diestrus 2 injected females only a small number of FSH cells could be detected on diestrus 2 at 23:00. This number increased markedly on proestrus at 14:00 and decreased on proestrus at 17:00. A similar evolution was observed in diestrus 1 testosterone injected females, but the number of FSH cells appeared higher at any stage of autopsy in these females than in diestrus 2 injected females and in control rats. In control females, numerous LH cells were observed on diestrus 2 at 23:00. The number of these cells was diminished on proestrus at 14:00 and still more at 17:00. On the contrary few LH cells were detected in testosterone injected females on the evening of diestrus 2. An increase of these cells occurred on proestrus at 14:00, followed at 17:00 by only a weak diminution as established by comparison with control animals. An inhibition of FSH release and a suppression of the proestrus surge of LH were therefore supposed to cause, on one hand, the slowing up of follicular growth observed in diestrus 1 injected females and, on the other hand, the blockage of ovulation noted in both diestrus 1 and diestrus 2 treated animals.
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    URL: http://dx.doi.org/10.1007/BF00307078
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    The granule-containing cell somata in the superior cervical ganglion of the rat, as studied by a serial sampling method for electron microscopy (1973)
    Springer
    Cell & tissue research 141 (1973), S. 331-345 
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    ISSN: 1432-0878
    Keywords: Sympathetic ganglion ; Granule-containing cells ; Synapses ; Three-dimensional analysis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The surface of 4 granule-containing cells, in a cluster within the rat superior cervical ganglion, was studied by a serial sampling technique for electron microscopy. The result shows that all the 4 cells receive one, or three afferent synaptic boutons from the preganglionic fibers impinging upon their somata, and a somatic efferent synapse exists at two locations on each soma of the 2 of these cells. The postsynaptic element of the efferent synapse is observed to be represented by non-vesiculated and vesiculated segments of dendrites, soma and a possible axon collateral of the adrenergic principal neuron of the ganglion. There is a remarkably constant development of the attachment plaque between the granule-containing cells themselves, representing 1.7–2.3% of surface area for each cell. The surface area exposed to the extracellular space (covered only by a basal lamina) varies from 0.1 to 2.3% of the total perikaryal surface of the 4 cells. A tendency is noted that those cells without efferent synapses possess a more extensive area exposed to extracellular space than those forming somatic efferent synapse to the postganglionic elements.
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    Ultrastructural features of rat pituicytes in organotypic culture (1973)
    Springer
    Cell & tissue research 143 (1973), S. 107-116 
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    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Pituicytes ; Organotypic culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes of adult rats have been explanted and organ-cultured for 5–10 days. While perivascular cells and neurosecretory fibers undergo a progressive degeneration, scattered pituicyte-like cells are observed mostly associated with each other in number of two or three cells for group. Cultured pituicytes are quite similar to in vivo pituicytes except for some particular features as the shape of the nucleus and the number of dense bodies. Furthermore they share with the in vivo pituicytes the phagocytic capacity which appears even increased as far as neurosecretory fibers are concerned. Finally, degenerating pituicytes and free lipid droplets are observed in the intercellular spaces: the significance of these facts is discussed and tentatively interpreted. The organotypic culture of the neural lobe seems to represent an experimental model useful to obtain a relatively pure population of pituicytes.
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    URL: http://dx.doi.org/10.1007/BF00307454
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    Le système nerveux des cténaires (1973)
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    Cell & tissue research 143 (1973), S. 117-133 
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    ISSN: 1432-0878
    Keywords: Nervous system ; Ctenophores ; Intra-mesogleal nervous system ; Synapses ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural evidence is given of the occurrence of nervous elements in the mesoglea of Ctenophores based on the presence of the typical synapses of this phylum. In Beroids, nervous fibers from the ectodermal nerve-net cross the epithelial basal membrane and run through the mesoglea; they are devoid of any ensheathing cell. These neurites build highly differentiated synapses upon the muscles and upon peculiar cells, tentatively named mesenchymal cells. In Cydippids, nerve fibers and nerve cell-bodies have been observed in the mesoglea of the tentacles. The mesogleal core of each tentacle contains mesenchymal cells and a thick strand of neurons and neurites, forming a kind of elongated ganglion. Neurites of either the axial neurones or the epithelial nerve-net neurones form numerous radial nerve strands across the tentacular muscles. Interneural, neuro-muscular and neuro-mesenchymal junctions are very frequent in the tentacle. As far as the organization of the mesoglea is concerned, the Ctenophora thus appear closer to Turbellaria than to Cnidaria.
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    New types of endoplasmic reticulum in neurons of the paracervical ganglion of the rat (1973)
    Springer
    Cell & tissue research 143 (1973), S. 505-515 
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    ISSN: 1432-0878
    Keywords: Endoplasmic reticulum ; Paracervical ganglion (Rat) ; Neurosecretion ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two new types of structure of the cytoplasm of an autonomic neuron were described: (1) Inclusions of the rough ergastoplasmic reticulum, which were named “ergastosomes”, contain finely granular material with moderately electron opaque staining with both glutaraldehyde-OsO4 and KMnO4 fixations. A short comment was made on the nature of the contents of the ergastosomes. (2) Tubular formations of endoplasmic reticulum were found in the axons and/or dendrites of the paracervical ganglion.
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    Electron microscopic study of rat pituitary primordium in organ culture (1973)
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    Cell & tissue research 146 (1973), S. 453-461 
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    ISSN: 1432-0878
    Keywords: Hypophysis ; Primordium ; Rat ; Organ culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To see whether adenohypophysial tissue has the capacity of self-differentiation, Rathke's pouch together with part of the neurohypophysial primordium was isolated from 12-(Group A), 14- (Group B) and 15-day-old (Group C) rat fetuses and cultivated for 9, 6 and 5 days, respectively. Electron microscopic examination of these explants showed many adenohypophysial cells containing electron dense granules, indicative of cytodifferentiation in all groups. Three cell types were distinguishable on the basis of the size of their granules. Variable amounts of neurohypophysial tissue were seen in some explants of Groups B and C, but not A. This “pars nervosa” contained pituicytes with lipid-like inclusions in their cytoplasm but no neurosecretory axons. The adenohypophysial cells abutting on the pars nervosa were arranged rather regularly like cells of the pars intermedia which contained a few granules of about 200 mμ diameter. From these data it is concluded that in rats granule formation in the adenohypophysial primordial cells starts in the absence of hypothalamic neurosecretory substances. It is uncertain from this study whether these cells actually contain hypophysial hormones.
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    The locus coeruleus of cat (1974)
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    Cell & tissue research 149 (1974), S. 205-221 
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    ISSN: 1432-0878
    Keywords: Locus coeruleus ; Tegmentum ; Mesencephalon ; Adrenergic centers ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The locus coeruleus of cat is populated by two types of neurons: medium sized ones, with plump cell bodies and relatively short dendrites; and small ones, with triangular bodies and relatively long dendrites. The former type is regarded here as typical of the centre, whereas the second type could simply represent displaced neurons from the adjacent griseum centrale. Electron microscopy failed to reveal any outstanding richness in pigment granules in kittens up to five weeks old. Very characteristic somatic appendages were found, mostly in the medium sized neurons. These somatic “spines” communicate with the perikaryon by means of a narrow neck region. A complex, multilayered, glial sheath surrounds the cells. This glial sheath is pierced by the somatic appendages, which are not surrounded by glia and make contact with axonal knobs. Typical dendritic spines appear to be absent. Axodendritic synapses are made on medium sized dendritic trunks. By and large, most of the synaptic vesicles present in the centre are of the small, clear-centered type. However, dense core vesicles extremely variegated in size and appearance were found, both in presynaptic and postsynaptic profiles. The possibility that dense core vesicles should be regarded as atypical lysosomes rich in by-products of the metabolism of catecholamines (melanine) has been considered.
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    In vitro analysis of the cellular localization of luteinizing hormone releasing factor (LRF) in the basal hypothalamus of the rat (1974)
    Springer
    Cell & tissue research 149 (1974), S. 371-378 
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    ISSN: 1432-0878
    Keywords: LRF ; Hypothalamic localization ; Rat ; Ependyma ; Glia ; Light and electron microscopic Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light and electron microscopic autoradiographic analysis of the medial basal hypothalamus of rat brains incubated for 30 and 60 minutes in tritiated luteinizing releasing factor (3H-LRF) revealed selective uptake in the form of silver grains over specialized ependyma (tanycytes) and perivascular glial cells in the palisade-contact zone of the median eminence. The functional capacity of tanycytes and glia are discussed in light of these data.
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    The ultrastructure of the duct system in the rat extraorbital lacrimal gland (1973)
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    Cell & tissue research 144 (1973), S. 453-466 
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    ISSN: 1432-0878
    Keywords: Lacrimal gland ; Rat ; Duct system ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The duct system of the rat exorbital lacrimal gland consists of intercalated ducts, interlobular ducts and excretory ducts. The morphological changes from one type of duct to the next are gradual. At the light microscopical level this consists of a change from a bilaminar epithelium in the intercalated ducts to an epithelium, consisting of approximately three layers — which may be pseudostratified — in the excretory ducts. The basal layer of the intercalated ducts consists of myoepithelial cells, whereas the inner epithelial cells may have both a secretory and an electrolyte transporting function. The interlobular duct epithelium contains many cells with deep infoldings of the basolateral plasma membranes and associated mitochondria, suggesting a similar function to the striated duct epithelium in salivary glands. Numerous basal cells in this epithelium have tentatively been interpreted as unusual myoepithelial cells. Nerve terminals have been observed in the ductal epithelium.
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    Failure to demonstrate serotonergic neurons in the myenteric plexus of the rat (1974)
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    Cell & tissue research 150 (1974), S. 493-496 
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    ISSN: 1432-0878
    Keywords: Serotonin ; Neurotransmitter ; Myenteric plexus ; Rat ; Histofluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Several recent studies suggested that serotonergic neuron-like elements are present in the guinea pig ileum. The present paper reports an extensive study of the digestive tract of the rat with the use of a histofluorescence technique. Administration of the serotonin precursor, tryptophan, associated with a monoamine oxidase inhibitor, did not allow histochemical demonstration of rapidly fading, yellow fluorescent, 6-hydroxydopamine-resistant neurons; conversely such neurons were readily detected in the brain. It is concluded that serotonergic neuron-like elements cannot be detected histochemically in the rat myenteric plexus area after chemical sympathectomy.
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    Studies on the juxtaglomerular apparatus (1974)
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    Cell & tissue research 151 (1974), S. 457-469 
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    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus ; Rat ; Adrenalectomy ; Renin and secretory granules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Reaktion des juxtaglomerulären Apparates auf Adrenalektomie wurde untersucht. Im Stadium der Nebenniereninsuffizienz, sechs Tage nach der Operation, wurde quantitativ morphometrisch eine Abnahme der Volumendichte der Sekretgranula (von 32% auf 16%) festgestellt. Golgi-Apparat und Ergastoplasma proliferieren stark, wobei insbesondere die erweiterten Cisternen des Ergastoplasmas auffallen.
    Notes: Summary The response of the Juxtaglomerular apparatus to bilateral adrenalectomy was studied in rats. After the sixth postoperative day, symptoms of severe adrenal insufficiency had developed. In the Juxtaglomerular cells, the volume density of the secretory granules decreased from 32% to 16%. The Golgi apparatus and rough endoplasmic reticulum underwent considerable proliferation, the latter showing strikingly enlarged cisternae.
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    Sex differences in adrenocortical structure and function (1974)
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    Cell & tissue research 151 (1974), S. 525-536 
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    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Sex differences ; Gonadal hormones ; Karyometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Adrenal glands of adult female rats are heavier than the glands of corresponding male rats. Postpubertal orchiectomy increases the adrenal weight, an effect restored by testosterone replacement. Under the same conditions ovariectomy of 8 weeks duration does not change the adrenal weight while estradiol replacement enhances the relative adrenal weight. Karyometric studies have shown that nuclei in the female zona fasciculata cells are larger (app. 18%) than those of the male. Similar but only slight differences (2%) were observed in the zona reticularis. Orchiectomy results in enlargement of cell nuclei within all zones of the adrenal cortex; testosterone replacement has the opposite effect. Ovariectomy of 8 weeks duration slightly enhances the volume of nuclei of the zona glomerulosa cells, has no effect on the nuclei of the zona fasciculata and reduces the volume of nuclei in the zona reticularis. Estradiol replacement reduces the volume of nuclei of the zona glomerulosa cells but increases nuclear volume in the zona fasciculata and in the zona reticularis. Thus testosterone has an inhibitory effect on the adrenal cortex of the rat while the physiologic effect of estradiol on the morphology of this gland, particularly on the zona fasciculata cells is rather dubious. The author wishes to thank Mrs. B. Westerska and Miss K. Siejak for excellent technical assistance.
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    Sex differences in adrenocortical structure and function (1974)
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    Cell & tissue research 151 (1974), S. 537-547 
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    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Sex differences ; Gonadal hormone ; Stereologic studies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Adult female rats have heavier adrenals than males. Orchiectomy increases the adrenal weight, an effect reversed by testosterone. Neither ovariectomy nor estradiol replacement has an effect on absolute adrenal weight. The stereologic analysis of the volume fractions of particular adrenocortical zones have shown that the volume fraction of the zona glomerulosa in females is smaller as compared with males. On the contrary, the volume fractions of the fasciculata and reticularis zones are higher in female than in male rats. In both sexes gonadectomy and gonadal hormone replacement has an effect on the volume fractions of particular adrenocortical zones, these changes being more pronounced due to orchiectomy or testosterone replacement. The adrenal cortex of all experimental groups contains a similar quantity of parenchymal cells. The cytoplasm volume of a single adrenocortical cell is higher in all zones of the female adrenals as compared with the male. Orchiectomy increases the volume of the cytoplasm in fasciculata and reticularis cells. This effect was reversed by testosterone. Neither ovariectomy nor estradiol replacement has an effect on the volume of the cytoplasm in the fasciculata and reticularis cells. These studies have shown that sex differences with regards to rat adrenal size and weight depend upon the “physiologic atrophy” of the male adrenal cortex, while neither ovariectomy (8 weeks after operation) nor estradiol replacement has a conspicuous effect on the morphologic changes of this gland.
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    The ultrastructure of lateral line sense organs in the juvenile salamander Ambystoma mexicanum (1974)
    Springer
    Cell & tissue research 152 (1974), S. 283-292 
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    ISSN: 1432-0878
    Keywords: Sense organ ; Lateral line ; Synapses ; Ambystoma mexicanum ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Lateral line organs in young salamanders of the species Ambystoma mexicanum were investigated with scanning and transmission electron microscopy. They were found to differ from the lateral line organs in adult animals (1) by being lower, having short hair cells and supporting cells, (2) by the hair cells having areas of lateral contact, (3) by the occasional presence, at the edge of the organ, of hair cells at an early developmental stage. Two types of nerve endings are seen: (1) afferent, and (2) less commonly, efferent vesiculated ones. Synaptic bodies have been seen in the cytoplasm without association to afferent synapses.
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    Quantitative data on the fine structural organization of the palisade zone of the median eminence (1973)
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    Cell & tissue research 136 (1973), S. 111-120 
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    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Granular vesicles ; Ultrastructure ; Quantitative evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to characterize different sub-zones in the palisade zone of the rat median eminence, quantitative ultrastructural parameters were applied to brains fixed in aldehyde-osmium tetroxide. The palisade zone has been subdivided in 4 successive sub-zones. Increasing numbers of granular vesicles (GV), especially those smaller than 110 nm, are observed from dorsal to ventral sub-zones. There also are more GV per unit area of nervous tissue in the perivascular than in the more dorsal sub-zones. The individual nerve profiles exhibit a larger size in the perivascular layer than in the more dorsal areas, whereas the number and size of nerve profiles devoid of vesicles diminish from dorsal to ventral. As a consequence more GV occur in the perivascular nerve profiles. In the GV containing nerve profiles the concentration of GV is, however, constant in the different sub-zones. A fluctuating size of the preterminal and terminal parts of the nerve fibres is suggested.
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    Ultrastructural changes in rat epididymis after vasectomy (1973)
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    Cell & tissue research 136 (1973), S. 177-182 
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    ISSN: 1432-0878
    Keywords: Rat ; Epididymis ; Effect of vasectomy ; Spermatozoa ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Epididymal biopsies from rats that had undergone unilateral or bilateral vasectomies from one to eight months previously were compared with biopsies from their contralateral side or from normal controls to ascertain what ultrastructural changes had occurred. After vasectomy, spermatozoa appeared to dissolve in the lumen of the caput epididymidis and to be absorbed by the principal cells. About 5 weeks after vasectomy, numerous lamellar accumulations became apparent in the supernuclear region. Their resemblance to lysosomes or residual bodies was confirmed by an acid phosphatase reaction. After 10 weeks, similar lamellar and polymorphic accumulations on the contralateral side of animals with unilateral vasectomies indicated that resorption had also increased on the unligated side.
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    Zur Feinstruktur des dorsalen Riesenfasersystems im Bauchmark des Regenwurms (1973)
    Springer
    Cell & tissue research 139 (1973), S. 369-396 
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    ISSN: 1432-0878
    Keywords: Synapses ; Giant fibres ; Ventral nerve cord ; Lumbricus terrestris L. ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die proximalen Kollateralen der dorsalen Riesenfasern des Regenwurms wurden in Serienschnitten vom Soma bis zum Eintritt in die Riesenfaser verfolgt und im Hinblick auf ihre Feinstruktur und ihre synaptischen Kontakte Untersucht. Es finden sich sowohl chemische als auch elektrische Synapsen. Ihre Feinstruktur wird mit der bekannter Synapsen anderer Wirbellosen und Wirbeltiere verglichen. In beiden Riesenfasersystemen kommen efferente chemische Synapsen mit feinen postsynaptischen Verzweigungen vor, die anscheinend von Bauchmark-Motoneuronen stammen. Das Axon der medianen Riesenfaser weist darüber hinaus nur noch eine elektrische Synapse mit den Rieseninterneuronen auf. Demgegenüber erhalten die Kollateralen der lateralen Riesenfasern zahlreiche Afferenzen, die zum Teil als sensorische Fasern der Epidermis, multisegmentale Fasern der Hauptfaserzüge und Rieseninterneurone identifiziert werden konnten. Weitere Afferenzen stammen vermutlich von unisegmentalen Interneuronen her. Beide lateralen Riesenzellaxone bilden außerdem miteinander eine elektrische Chiasma-Synapse mit besonderen Membraneinfaltungen.
    Notes: Summary The proximal collaterals of the dorsal giant fibres of the earthworm were traced through serial sections from the cell bodies to the giant axons. Their structure and synaptic connections were examined. There are chemical as well as electrical synapses. Their fine structure is compared to that of other known invertebrate and vertebrate synapses. Both giant fibre systems have efferent chemical connections with thin postsynaptic arborizations which probably belong to ventral cord motoneurons. Moreover the median giant axon is connected by an electrical synapse with the giant interneurons. The lateral giant collaterals on the contrary receive many afferences through chemical synapses which were partly identified as sensory fibers from the epidermis, multisegmental axons from the main fibre bundles or giant interneurones. Other afferences probably come from unisegmental interneurones. In addition both lateral giant axons form an electrical chiasma synapse with special membrane folds.
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    A radioautographic study of the transport of 125I-labeled serum lipoproteins in rat aorta (1973)
    Springer
    Cell & tissue research 138 (1973), S. 223-237 
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    ISSN: 1432-0878
    Keywords: Aorta, endothelium ; Rat ; Transport of serum lipoproteins ; Radioautography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The transport of 125I-labeled serum lipoproteins through the aortic endothelium was studied by radioautography. Rat aorta and heart was perfused in vitro with a medium containing human very low density (VLDL), low density (LDL), high density lipoprotein (HDL), delipidated HDL apolipoprotein or rat HDL. In all lipoproteins more than 95% of the radioactivity was TCA precipitable and lipid radioactivity was from 2–4% in HDL, 4–6% in LDL, 7–15% in VLDL. After 18–60 min of perfusion and wash with unlabeled medium, most of the aortic radioactivity was TCA precipitable and the percent of lipid counts was similar to that in the original lipoprotein. Following perfusion with VLDL, LDL, or HDL the radioautographic reaction was seen over the endothelium, the subendothelial space and the inner media, and was separated by an unlabeled zone from the reaction present over the adventitia. Uniform labeling of the entire wall was found after perfusion with HDL apolipoprotein. The presence of silver grains over endothelial cells in regions rich in plasmalemmal vesicles suggested that these organelles participate in the transport of the labeled lipoprotein, as was shown for lactoperoxidase (Stein and Stein, 1972). The present data indicate that cholesterol may enter the aortic wall as a constituent of lipoprotein particles. Since an HDL particle carries less than 1/20 of the cholesterol present in a LDL particle, it seems that the lower susceptibility of the female to atheromatosis might be related to the higher ratio of HDL to LDL particles in the female serum.
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    Tagesrhythmische Veränderungen im Granulationsindex der juxtaglomerulären Zellen der Rattenniere (1973)
    Springer
    Cell & tissue research 137 (1973), S. 141-143 
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    ISSN: 1432-0878
    Keywords: Juxtaglomerular cells ; Rat ; Granulation index ; Diurnal rhythm ; Statistical evaluation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Granulations-Index der juxtaglomerulären epitheloiden Zellen der Rattenniere unterliegt tagesrhythmischen Schwankungen, wobei die berechneten Werte in den Nachtstunden significant höher sind als in den Tagesstunden.
    Notes: Summary Marked diurnal changes occur in the granulation index of the juxtaglomerular cells in the rat kidney. According to the results the night values are significantly higher than those obtained in daytime.
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    Suppression of somatotrophs in growth hormone injected rats (1973)
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    Cell & tissue research 140 (1973), S. 309-314 
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    ISSN: 1432-0878
    Keywords: Pituitary Gland ; Rat ; Somatotropin ; Cellular Response ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The response of somatotrophs to large doses of purified bovine growth hormone was examined in uninephrectomized rats drinking 1% sodium chloride in an attempt to prolong the action of the hormone. Growth hormone produced a triphasic response in the ultrastructure of somatotrophs. Uninephrectomy and salt alone induced no changes in somatotrophs as compared to unoperated animals consuming tap water. In the first phase (3 days) the cross sectional area of the cell increased, the size of the largest granule per cell as well as the number of granules per cell increased significantly. All these parameters then reached control level after 7 days of injections during a second phase. Suppression of somatotrophs by exogenous growth hormone was evident by 16 days (third phase) when the area of the cell, the size of the largest secretory granule as well as the number of granules per cell all decreased significantly. Somatotrophs apparently did not react to suppression by a lysosomal mechanism inasmuch as no increase in the number of lysosome-derived structures was seen even at 16 days.
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    A light and electron microscope study of the nervous system of Ceriantheopsis americanus (cnidaria, ceriantharia) (1973)
    Springer
    Cell & tissue research 141 (1973), S. 301-317 
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    ISSN: 1432-0878
    Keywords: Cnidaria ; Nervous system ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nervous system of juvenile and adult Ceriantheopsis americanus has been examined with the electron microscope. The nervous system is exclusively ectodermal, forming a plexus of fibres lying between the epithelium and the muscle layer. The plexus consists of three types of nerve fibre that vary in diameter from 0.1 to 20 μ, and a fourth type of fibre of uncertain nature. The reticulum, previously thought to be the ectodermal nervous system, is redescribed as the peduncles of epithelial supporting cells. Intraneural and neuromuscular synapses are described. About 97% of the interneural are polarized. The unpolarized synapses are a variety not previously described, consisting of a series of polarized zones, for which the name multipolarized synapse is proposed. Structurally, the interneural synapses are more complex than those previously seen in the Cnidaria. Presynaptic projections, periodic cleft densities, and a postsynaptic web are described. By contrast, the neuromuscular synapses bear no membrane specializations. On the basis of observed synaptic interactions of its components a preliminary model of the functional organization of the nervous system is proposed.
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    Karyometrische Untersuchungen am Nucleus suprachiasmaticus geblendeter Ratten (1973)
    Springer
    Cell & tissue research 143 (1973), S. 143-147 
    Details
    ISSN: 1432-0878
    Keywords: Rat ; Suprachiasmatic nucleus ; Blinding ; Retinohypothalamic connections ; Karyometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Radioaktiv markierte Aminosäuren werden bei Säugetieren nach intraokulärer Injektion nicht nur zu den primären optischen Kerngebieten, sondern auch in den Nucleus suprachiasmaticus des Hypothalamus transportiert (Moore und Lenn, 1972; Hendrickson, Wagoner und Cowan, 1972; Moore, 1973). Dieser Befund macht eine direkte Verknüpfung zwischen der Netzhaut und dem sekretorisch aktiven Nucleus suprachiasmaticus wahrscheinlich, obwohl mit Silbertechniken eine solche Verbindung nicht sicher nachgewiesen werden konnte. Karyometrische Studien am Nucleus suprachiasmaticus männlicher Wistar-Ratten zeigen 6 Tage nach beidseitiger Blendung eine signifikante Abnahme der Zellkerndurchmesser. Dieses Ergebnis spricht für eine Aktivitätsänderung der Neurone im Nucleus suprachiasmaticus geblendeter Ratten.
    Notes: Summary Intraocular injection of labeled amino acids results, in different mammals, in an accumulation of radioactive material not only in the primary optic centers but also within the hypothalamic suprachiasmatic nucleus (Moore et al., 1972; Hendrickson et al., 1972; Moore, 1973). This finding argues in favour of a direct connection between the retina and the secretory suprachiasmatic nucleus although silver techniques do not show such a pathway. In male Wistar rats the nuclear diameter of the suprachiasmatic neurons decreases significantly 6 days after bilateral experimental ablation of the retina. These results indicate an alteration in activity of the suprachiasmatic neurons in blinded rats.
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    Influence de la méthode de fixation sur l'observation des divisions cellulaires dans l'adénohypophyse du rat mâle (1973)
    Springer
    Cell & tissue research 143 (1973), S. 535-547 
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    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Rat ; Mitoses, topographic distribution ; Influence of fixation ; Light microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les mitoses de l'adénohypophyse du rat mâle ont été examinées comparativement après fixation par perfusion et après fixation par immersion. Après fixation par perfusion la répartition topographique des mitoses dans le parenchyme est homogène, et l'index mitotique est de 1,85 pour 1 000 cellules. Après fixation par immersion, la densité des mitoses décroit de la périphérie vers le centre, et l'index mitotique n'est que de 0,80 mitoses pour 1 000 cellules. La lenteur de pénétration du fixateur pendant l'immersion est tenue pour principal responsable des différences observées. Elle entraîne une modification de l'aspect des mitoses, telle que plus de la moitié d'entre elles ne sont pas identifiables et échappent aux comptages.
    Notes: Summary The mitoses of the adenohypophysis in male rats have been observed comparatively after fixation by perfusion and fixation by immersion. After fixation by perfusion, the topographic distribution of mitoses throughout the parenchyma is homogenous and the mitotic index is 1.85 for 1 000 cells. After fixation by immersion, the density of the mitoses is decreasing from the periphery towards the center and the mitotic index is only 0.80 for 1 000 cells. The slow penetration of the fixative during fixation by immersion is considered to be the main cause in the differences observed. This slow action causes a modification in the aspect of the mitoses, and more than fifty percent of them cannot be identified and escape to the counts.
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    URL: http://dx.doi.org/10.1007/BF00306772
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    Ultrastructural investigations of the palisade-shaped nerve fiber terminals of the normal hairs of rat's snout (1974)
    Springer
    Cell & tissue research 147 (1974), S. 259-269 
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    ISSN: 1432-0878
    Keywords: Nerve endings ; Hair ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Palisade-shaped nerve endings of the small normal hairs of the rat snout were examined with the electron microscope (fixation by perfusion). The terminals are located inside the ‘glassy membrane’ in the area of the neck of the hair root. The 10–20 radially arranged terminal axons are in direct contact with the basement membrane of the epithelium of the external root sheath. The axons are surrounded on all sides by leaf-shaped processes of the Schwann cells. The surfaces of these cell processes are marked by numerous vesicle-like invaginations (approx. 1000 Å dia.). Transverse sections from several areas of the palisadeshaped nerve endings are compared with longitudinal sections. In the upper area ‘empty’ vesicles (approx. 500–600 Å in diameter) occur, along with electron-dense vesicles (approx. 800–1100 Å in diameter); in the middle area, the axons are distended and contain accumulations of mitochondria.
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    The parietal layer of bowman's capsule in experimental hypertension (1974)
    Springer
    Cell & tissue research 147 (1974), S. 183-190 
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    ISSN: 1432-0878
    Keywords: Kidney ; Rat ; Bowman's capsule ; Experimental hypertension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The parietal layer of Bowman's capsule was examined in the rat in control animals and in animals made hypertensive by treatment with desoxycorticosterone acetatesaline and by clipping of the renal artery. At an early stage of elevation of blood pressure and, occasionally, prior to elevation of blood pressure, the epithelial cells of this layer showed basal cytoplasmic protrusion and reduplication accompanied by an increase in the thickness of the basement membrane. These changes preceded evidence of glomerular or renal arteriolar pathology. They presumably reflect either a response of this layer to increased blood pressure and modified glomerular function, or a direct effect of the factors that also induces blood pressure elevation. In either case, they imply a greater functional significance for the parietal layer than has usually been attributed to it.
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    URL: http://dx.doi.org/10.1007/BF00582793
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    The ultrastructure of the accessory sex organs of the male rat (1974)
    Springer
    Cell & tissue research 148 (1974), S. 57-67 
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    ISSN: 1432-0878
    Keywords: Prostate ; Rat ; Cyproterone ; Alterations ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The dorsal lobe and the coagulating gland of the rat prostate were studied after administration of the anti-androgenic compound Cyp A for varying periods (7–20 days). There was a general involution of the organs with macroscopic atrophy and reduced amount of secretory material. Ultrastructurally the cells were pale, contained less organelles as compared with the controls, loss of cytoplasm and reduction both of cell height and width. The major changes also included reduction of the Golgi area, the rough endoplasmic reticulum and the number of free ribosomes. Within the dorsal lobe prominent nuclear changes were found, comprising different types of intranuclear inclusions of membranous configurations. The alterations observed in the present study are similar to the changes which were found in castrated animals and are consistent with atrophy. The results are discussed in relation to the available biochemical and autoradiographic data on the different lobes.
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    URL: http://dx.doi.org/10.1007/BF00224318
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    Elementary granules, small vesicles and exocytosis in the rat neurohypophysis after acute haemorrhage (1972)
    Springer
    Cell & tissue research 125 (1972), S. 277-288 
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    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Exocytosis ; Freeze-etching ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural lobes of rats subjected to severe acute haemorrhage under sodium pentobarbitone anaesthesia were examined electron microscopically and the ultrastructure compared with that in anaesthetised and unanaesthetised controls. Changes in the localisation and numerical distribution of elementary granules and small vesicles in the neurohypophysial nerve endings of bled rats were consistent with the occurrence of exocytosis. The occurrence of “exocytotic profiles” was observed more frequently in freeze-etched tissue samples as compared with the material fixed for conventional electron microscopy. The ratio of small vesicles: elementary granules was shown to be significantly increased (P〈0.005) in the nerve endings of neural lobes from bled rats. Equally, the numbers of exocytotic profiles related to 1000 μm2 of neurohypophysial tissue area were significantly greater (P〈0.005) in bled rats.
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    Extracellular perivascular connective tissue space in the medial terminal nucleus of the accessory optic system in rats (1972)
    Springer
    Cell & tissue research 125 (1972), S. 289-294 
    Details
    ISSN: 1432-0878
    Keywords: Accessory optic system ; Rat ; Blood vessels ; Extracellular space ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of capillaries were found in the medial terminal nucleus of the rat accessory optic system. Type one capillaries are surrounded by glial processes and lack a perivascular space, whereas the type two capillaries and arterioles show a distinct extracellular perivascular space often filled with collagen fibrils. An internal as well as an external basal lamina lines these spaces. No fenestration of the endothelium was observed.
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    Further studies on synaptic junctions (1972)
    Springer
    Cell & tissue research 125 (1972), S. 415-431 
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    ISSN: 1432-0878
    Keywords: Synapses ; Rat ; Cerebral cortex ; Glutaraldehyde/E-PTA ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synaptic junctions in intact rat cerebral cortex have been examined following glutaraldehyde fixation and phosphotungstic acid (PTA) staining. In the presynaptic ending the network has a hexagonal arrangement, while the dense projections are regularly placed along the presynaptic membrane. Cleft densities occupy the intracleft region. The postsynaptic thickening extends uninterrupted along the length of the junction. Qualitatively, the majority of junctions fall into the ‘discontinuous-continuous’ category, in which the internal coat of the presynaptic membrane together with its associated dense projections is discontinuous along the length of the junction, whereas the postsynaptic thickening is continuous. By contrast, a small number of junctions are ‘continuous-continuous’. In an attempt to analyze the junctions quantitatively, nine indices were measured. Histograms of the size distributions of seven of these appear to be bimodal, and from this it is concluded that two junction populations may be distinguishable on quantitative grounds. It is also shown that the distance separating dense projections at the presynaptic membrane is of the order of 10–15 nm. This surprisingly low value has consequences for current ideas on the relationship between synaptic vesicles and dense projections, and these are discussed at length.
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    URL: http://dx.doi.org/10.1007/BF00306651
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    Die Feinstruktur der interstitiellen Grundsubstanz im inneren Nierenmark der Ratte bei verschiedenen Fixierungsarten (1972)
    Springer
    Cell & tissue research 125 (1972), S. 404-414 
    Details
    ISSN: 1432-0878
    Keywords: Renal medulla ; Rat ; Interstitial ground substance ; Fixation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Interstitium des inneren Nierenmarkes von Ratten wurde nach Anwendung verschiedener Fixierungsarten und Versuchsanordnungen elektronenmikroskopisch untersucht. Neben Bindegewebszellen und kollagenen Fibrillen enthält der interstitielle Raum bandförmige, basalmembranartige Strukturen, in deren weiträumigen Maschen zwei weitere Komponenten, nämlich ein feingranuläres und feinfilamentäres Material sowie kontrastreiche, globuläre Partikel liegen. Diese beiden Formelemente stellen sich bei den verschiedenen Fixierungsarten und Versuchsanordnungen unterschiedlich dar. Bei der feingranulären und feinfilamentären Komponente handelt es sich wahrscheinlich um interstitielles Blutplasma. Diese Deutung wird gestützt durch die morphologische Ähnlichkeit mit dem Blutplasma der Blutgefäße, die unterschiedliche Darstellbarkeit nach Glutardialdehyd-und Formalinfixierung sowie durch die Befunde nach Gefäßperfusion und Nierenvenenstauung. Das Verhalten der globulären Partikel nach OsO4-Einwirkung steht in Einklang mit der schon früher gegebenen Interpretation als präzipitierte saure Mukopolysaccharide. Ihr elektronenoptisches Bild wird im Vergleich zur bekannten makromolekularen Struktur der Mukopolysaccharid-Protein-Moleküle diskutiert.
    Notes: Summary The interstitial ground substance in the inner medulla of the rat kidney is examined electron microscopically after fixation with various fixation agents and under different experimental conditions. The papillary interstitium contains besides interstitial cells and few collagen fibrils basement membrane like material and two other components, fine granular-fibrillar elements and globular particles with heavy contrast. The appearance of the two latter interstitial components varies according to the different fixation agents used and to the experimental conditions. The fine granular and fine fibrillar material surrounds the globular particles numerously after glutardialdehyde-fixation but scarcely after formaldehyde-fixation. It increases after renal vein occlusion, but is diminished or absent, if the kidney is rinsed bloodfree. These results allow to conclude that this material represents interstitial bloodplasma. The behaviour of the globular particles after OsO4-fixation agrees well with the earlier interpretation according to which they represent precipitated acid mucopolysaccharides. Their electron microscopic appearance is discussed in comparison with the known macromolecular structure of the acid mucopolysaccharides.
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    Further studies on synaptic junctions (1972)
    Springer
    Cell & tissue research 125 (1972), S. 432-447 
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    ISSN: 1432-0878
    Keywords: Synaptosomes ; Synapses ; Rat ; Cerebral cortex ; Glutaraldehyde/E-PTA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Working with glutaraldehyde fixed, PTA stained rat cerebral cortex, the authors compared the ultrastructural features of synaptosomes with those of intact synaptic junctions. In general there is close correspondence between the two, although the cleft densities and postsynaptic focal densities of synaptosomes show a greater degree of focalization than their counterparts in synaptic junctions. The dense projections have similar profiles in both preparations, but are more difficult to distinguish clearly in synaptosomes on account of the closer packing of the presynaptic network around their apices. The limiting membrane of the presynaptic terminal is usually visible in synaptosomes, but not in synaptic junctions. Comparing the preparations quantitatively reinforces the qualitative findings, and points to their overall similarity. However a number of the indices in synaptosomes are significantly smaller than the corresponding ones in synaptic junctions, and this points to the operation of a shrinkage factor during fractionation procedures. This is confined to the pre- and post-synaptic components and does not affect the intervening contact region. Histograms of the size distributions of the indices are similar to those obtained for intact synaptic junctions, the majority displaying two peaks. It is concluded that synaptosomes accurately reproduce the major ultrastructural features of synaptic junctions.
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    On the fine structure of alteration of the adrenal cortex in hypophysectomized rats (1972)
    Springer
    Cell & tissue research 125 (1972), S. 480-496 
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    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Normal ; Hypophysectomy ; Structural alteration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adrenal cortex of normal and hypophysectomized rats was observed by electron microscopy 5–90 days after the operation and, chiefly, the degeneration mechanism of the cortical tissue was discussed. In normal rats mitochondrial inner structures are generally tubular in shape in glomerulosa cells, vesicular (and tubulo-vesicular) in fasciculate cells and tubulo-vesicular (and vesicular) in reticularis cells. Some mitochondria in a few glomerulosa cells show long straight tubular crests in normal as well as hypophysectomized rats. Usually lipid droplets in normal glomerulosa, fasciculate and reticularis cells are surrounded by elements of smooth endoplasmic reticulum, which are very closely associated with mitochondria. About 10–25 days after hypophysectomy, most mitochondria in fasciculate and reticularis cells show tubular crests, and numerous electron lucent lipid droplets are accumulated in these cells. These droplets occupy most parts of the cytoplasm and are sometimes in contact with one another or with mitochondria. The elements of smooth endoplasmic reticulum and Golgi apparatus are markedly reduced in number and size. About 10–90 days after the hypophysectomy, the degenerative cortical cells containing irregularly shaped nuclei, heterogeneously dense bodies in various sizes, and a large number of electron lucent lipid droplets are seen. The author speculates that most fasciculate and reticularis cells degenerate because of a disorder in the lipid metabolism, since ACTH release, which is necessary for synthesis of corticosteroid hormones from cholesterol, is absent in hypophysectomy. The fatty degeneration of the fasciculate and reticularis cells is considered to be a main cause for attenuation of the cortical tissue. Sometimes atrophied cortical cells without lipid droplets are also found 60–90 days after hypophysectomy.
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    The ultrastructure of the accessory sex organs of the male rat (1973)
    Springer
    Cell & tissue research 144 (1973), S. 167-178 
    Details
    ISSN: 1432-0878
    Keywords: Prostate ; Rat ; Castration ; Alterations ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ventral, lateral and dorsal lobes of the rat prostate were studied 2, 3, 5, 7 and 21 days after castration. The major changes were a general reduction of the Golgi area and the RER. The cells became pale and contained less organelles compared with the normals. One of the most conspicuous changes were enormous autophagic vacuoles which were present already after 2 days, seemed to reach a numerical peak 3 days after castration and were seldom encountered after 7 days. Increased number of dense bodies were found within the same period. Lipid droplets were observed in the basal cytoplasm of the epithelial cells, especially in the ventral lobe. The basal cells showed the same involution as in the ordinary epithelium. In addition, macrophages were relatively numerous, and between the epithelial cells also lymphocytes were found. The results are discussed in relation to biochemical data on the different lobes.
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    The ultrastructure of the accessory sex organs of the male rat (1973)
    Springer
    Cell & tissue research 144 (1973), S. 179-189 
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    ISSN: 1432-0878
    Keywords: Seminal vesicles ; Coagulating Gland ; Rat ; Castration ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The seminal vesicles and the coagulating gland of the rat were studied 2, 3, 5, 7 and 21 days after castration. The major changes within the seminal vesicles were primarily formation of whorls of the rough endoplasmic reticulum (RER), followed by a general atrophy with a numerical reduction of the RER-profiles, and with general simplification of the cytoplasm due to loss of the organelles. It was a gradually reduction of secretion granules, diminution of the Golgi apparatus, formation of pigment bodies and autophagic vacuoles. Lipid droplets were observed in the basal cytoplasm of the epithelial cells. In the coagulating gland, similar changes occurred within the Golgi area and the lysosome complex. On the other hand, cisternae of the basal endoplasmic reticulum tended to persist in many cells. The similarity in response strongly suggests that the pathogenetic mechanisms are similar in both organs, i.e. atrophy due to deprivation of the androgenic stimulus. The deprivation of androgen gave rise to an inflammatory-like process with infiltration of lymphocytes and macrophages. The increased number of macrophages may indicate that they contribute in some way to the involution of the prostate by removing the material in the autophagic vacuoles.
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    Ultrastructure of mucosal mast cells in normal and compound 48/80-treated rats (1974)
    Springer
    Cell & tissue research 150 (1974), S. 95-105 
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    ISSN: 1432-0878
    Keywords: Mucosal mast cells ; Rat ; Compound 48/80 ; Degranulation, Release ; Light microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mast cells in the tongue and lamina propria of the duodenal mucosa, representing two cell types with different morphological, histochemical and functional properties have been studied under the electron microscope. Both cell types were found to contain similar moderately electron dense and homogeneous granules surrounded by a tight membrane constituting the basic ultrastructural characteristics of mast cells. The mucosal mast cells, however, contained fewer granules per cell and the individual granules often exhibited considerable variation in size. In addition the mucosal mast cells, unlike those of the tongue, peritoneum and skin, had a smooth plasma membrane lacking microvilli and possessed irregularly shaped or lobulated nuclei. In the tongue mast cells, administration of Compound 48/80 caused the formation of vacuoles around the granules, expulsion of granules from the cells and disintegration of the granular matrix, but no changes that could be attributed to 48/80 could be found in the mucosal mast cells.
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    The distribution of synapses along the spinal cord of an amphibian embryo: An electron microscope study of junction development (1974)
    Springer
    Cell & tissue research 153 (1974), S. 227-244 
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    ISSN: 1432-0878
    Keywords: Synapses ; Embryo (Xenopus laevis) ; Spinal cord ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rostro-caudal gradient of differentiation found in vertebrate embryos has been utilized to examine the sequence of synaptic junction development in the spinal cord of Xenopus laevis at a late embryonic stage. Uniform samples were taken at various points along the cord of a stage 27 embryo and examined in the electron microscope. The general ultrastructure of the cord demonstrated the rostro-caudal gradient of development. The sequence of synaptic junction development was like that in the cervical region (Hayes and Roberts, 1973). “Membrane-vesicle clusters” and “immature” synaptic junctions were found most caudally followed by synaptic junctions, first with cleft and subsynaptic membrane density, then with only cleft density and finally, most rostrally, with cleft, subsynaptic membrane, and subsynaptic cytoplasmic density. Mature synaptic junctions were found in increasing numbers from the mid to anterior trunk cord and could mediate alternating trunk flexions made by the embryos at this stage of development. “Membrane-vesicle clusters” were found near processes containing irregular vesicles and also near membrane outlines. These may be signs of dendritic growth. “Membrane-vesicle clusters” were also found in varicosities, facing the space around the spinal cord and in nerve fibres peripherally between the skin and myotomes. This suggests an association of early stages in synaptogenesis with axon growth. This and other possible inferences about axon and dendrite growth in relation to synaptogenesis are discussed.
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    Kinetics of gametogenesis (1974)
    Springer
    Cell & tissue research 154 (1974), S. 443-470 
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    ISSN: 1432-0878
    Keywords: Oocytes and T-prospermatogonia ; Rat ; Quantitative analysis ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Bei der Ratte findet die sexuelle Differenzierung der Gonade zwischen dem 14. und 15. Tag post conceptionem (p.c.) statt. Während dieser Zeit teilen sich die Oogonien und deren Parallelpopulation—die M-prospermatogonien (multiplying prospermatogonia) oder I-Gonocyten—sehr häufig. Um den 17. Tag p.c. tritt die letzte Generation der Oogonien bzw. der M-prospermatogonien in die Mitose. Die Mitosen bilden häufig “synchronisierte Gruppen”. Die postmitotischen Kerne ihrer Tochterzellen—der Oocyten und der T 1 prospermatogonien (primary transitional prospermatogonia) oder II-Gonocyten—sind klein. Ihr Chromatin ist in Form gröberer Schollen der Kernmembran angelagert. Auf diese Weise kommt das typische “krustenförmige” Aussehen bzw. die Ähnlichkeit mit den Prophasen der Oogonien und M-prospermatogonien zustande. Die Oocyten durchlaufen zunächst die G1-phase (etwa 10 Std Dauer) und treten dann—am Ende des Präleptotänstadiums—in die S-phase. Dann passieren sie die verschiedenen Stadien der meiotischen Prophase und treten vom 3. Tag post partum (p.p.) ab in das Dictyotänstadium. Die T1-prospermatogonien hingegen befinden sich etwa 10 Tage lang in der G1-phase, ohne wesentliche morphologische Veränderungen aufzuweisen. Vom 4. Tag p.p. an durchlaufen sie die S-Phase. Die S-Phasen-Dauer (D-S) beider Zellarten beträgt 11.5 Std und wurde durch Doppelmarkierung mit 14C- und 3H-Thymidin bestimmt. Als am besten geeignete Termine für die Bestimmung der D-S erwiesen sich bei den Oocyten der 18. Tag p.c. und bei den T1-prospermatogonien der 5. Tag p.p. Zu diesen beiden Zeitpunkten war die Anzahl der in die S-phase ein-und austretenden Oocyten bzw. T1-prospermatogonien gleich, die Zellen in S-phase befanden sich im “steady state”. Das Kernvolumen der Oogonien und M-prospermatogonien ist etwa doppelt so groß wie das der postmitotischen Oocyten und T1-prospermatogonien. Bis zum 5. Tage p.p. nimmt das Kernvolumen der Oocyten und T1-prospermatogonien um etwa das Fünffache zu. Der Degenerationsindex der Oocyten liegt wesentlich höher als der der T1-prospermatogonien; er ist postnatal besonders hoch. Aus den T1-prospermatogonien gehen am 4. und 5. Tage p.p. durch Teilung die T 2-prospermatogonien (secondary transitional prospermatogonia) hervor. Die Kerne dieses Zelltyps sind etwas kleiner also die der T1-prospermatogonien. Die T2-prospermatogonien treten am 6. Tage p.p. in die Mitose; es entstehen die ersten A-spermatogonien.
    Notes: Summary In the rat (Wistar-WU) sexual differentiation of the gonads occurs between days 14 and 15 post conception (p.c.). At this time the oogonia and their parallel population — the M-prospermatogonia (I-gonocytes)—divide rapidly. On about day 17 p.c., the last generation of oogonia and M-prospermatogonia, frequently arranged in synchronized clusters, enters mitosis. The postmitotic nuclei of their daughter cells—oocytes and T 1-prospermatogonia (II-gonocytes)—are small; coarse flakes of chromatin are associated with the nuclear membrane causing the typical “crustlike” appearance and the similarity with the prophases of oogonia and M-prospermatogonia. After the oocytes have passed a G1-phase of approximately 10 hr, they enter the S-phase at the end of the preleptotene stage. Then they pass the different stages of the meiotic prophase until they enter the dictyate stage from 3 day post partum (p.p.) onwards. The T1-prospermatogonia, on the other hand, spend a long G1-phase of about 10 days without any conspicuous morphological change before entering the S-phase from day 4 p.p. onwards. The duration of the S-pbase (D-S) of both cell types—oocytes and T1-prospermatogonia—as determined by the double labeling method with 14C- and 3H-thymidine is found to be 11.5 hr. The most favourable time for determining the D-S was day 18 p.c. for the oocytes and day 5 p.p. for the T1-prospermatogonia. On these two days the balance was reached between the cells entering and leaving the S-phase. The nuclear volumes of the postmitotic oocytes and T1-prospermatogonia are approximately half the size of those of their precursors. Until day 5 p.p. the nuclear volumes of the oocytes and T1-prospermatogonia increase about fivefold. The degeneration index of the oocytes is considerably higher than that of the T1-prospermatogonia; postnatally it is especially high. T 2 prospermatogonia arise by mitosis of the T1-prospermatogonia on day 4 and 5 p.p. The nuclei of this cell type are smaller than those of T1-prospermatogonia. T2-prospermatogonia enter mitosis on day 6 p.p and give rise to A-spermatogonia.
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    Development of serotonin-containing cells and the sympathetic innervation of the habenular region in the rat brain (1974)
    Springer
    Cell & tissue research 155 (1974), S. 231-243 
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    ISSN: 1432-0878
    Keywords: Pinealocyte-resembling cells ; Habenular region ; Sympathetic nerve fibres ; Ontogenetic development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cells of the pineal gland, the pineal stalk, and the lamina intercalaris contain 5-HT and are innervated by sympathetic nerve fibres. These peripheral nerve fibres continue rostrally from the lamina intercalaris and run into the central nervous tissue of stria medullaris and the habenular nuclei. Pharmacological treatment to increase the cellular 5-HT content revealed that the sympathetic fibres are in close relation to yellow fluorescent cells embedded in the brain tissue. These yellow fluorescent cells develop very late in the ontogenetic development (three weeks or more postnatally) and are preceded by ingrowth of sympathetic fibres into the brain tissue. The results support the hypothesis that the cells found in the habenular region are of pinealocyte rather than neuronal nature, but it is possible that they differ in certain aspects from the cells of the pineal gland proper.
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    Ultrastructure du lobe postérieur de l'hypophyse du rat et ses modifications au cours de l'excrétion de vasopressine (1970)
    Springer
    Cell & tissue research 108 (1970), S. 357-379 
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    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Rat ; Vasopressin release ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Le lobe postérieur de l'hypophyse a été examiné sur coupes ultrafines chez 45 rats (24 normaux, 17 déshydratés respectivement 1, 2 et 4 jours, et 4 anesthésiés à l'éther), après fixation au glutaraldéhyde ou selon la méthode de Karnovsky, post-fixation osmiée et double contraste à l'acétate d'uranyle et au citrate de plomb. Des fibres neurosécrétoires sombres et claires sont reconnaissables, mais les données manquent encore pour interpréter cette différence. Des densifications juxta-membranaires sont observées dans les terminaisons neurosécrétoires là où se trouvent des amas de microvésicules. Des fibres neurosécrétoires traversent parfois des pituicytes; il est aussi souvent observé des fibres, chargées de granules, libres dans un espace péricapillaire. Les espaces péricapillaires, ramifiés en tous sens loin des vaisseaux, développent une large surface de contact avec les extrémités nerveuses et les prolongements de pituicytes. Dans des conditions techniques bien contrôlées, la déshydratation n'entraîne pas de modifications appréciables des granules de neurosécrétat après 24 h. Ensuite les granules sont diminués en nombre, de façon très considérable le 4e jour; mais les granules restants ont un contenu dense normal; jamais il n'a été observé d'aspects de ≪granules vides ≫. Après anesthésie prolongée à l'éther, il n'y a aucune modification visible ni du nombre, ni de la densité des granules. Ces observations sont discutées quant au mécanisme de l'excrétion de vasopressine; elles sont en faveur de l'existence de deux pools hormonaux, l'un libre et rapidement disponible, l'autre plus fortement lié et certainement contenu dans les granules jouant le rôle de réserve. Toutefois un mécanisme d'exocytose granulaire ne peut être formellement exclu.
    Notes: Summary Hypophysial neural lobes of 45 rats (24 controls, 17 dehydrated resp. 1, 2 and 4 days, and 4 ether anesthetized) were fixed either with glutaraldehyde or according to Karnovsky and post-fixed in osmium tetroxyde; ultrathin sections were stained by uranyl acetate and lead citrate. Dark and clear neurosecretory fibres were observed, but sufficient data are still lacking for a valuable interpretation of these aspects. Juxta-membraneous densifications are visible in limited areas of neurosecretory terminals where clusters of microvesicles are present. Neurosecretory fibres happen to be completely encircled by pituioyte cytoplasm; fibres loaded with elementary granules are frequently encountered running free in a pericapillary space. Pericapillary spaces stretch out branching far away from vessels, resulting in a widespread contact with nerve terminals and pituicyte processes. In accurately controlled technical conditions, dehydratation does not result in any noticeable change of neurosecretory granules after 24 h. A decrease of the number of granules follows and is extremely conspicuous after 4 days; though, remaining granules keep a normal dense content, and aspects of “empty granules” have never been observed. After prolonged ether anesthesia, no visible change either in number or electron density of granules was observed. These findings are discussed in consideration of the mechanism of vasopressin release; they support the hypothesis of two hormonal pools, one of which would be free and rapidly available for release, the other being more tightly bound and certainly located in granules representing a storage site. Though granular exocytosis cannot be absolutely excluded.
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    Quantitativ-morphologische Untersuchungen an Herzmuskelzellen von normalen und hypoxischen Ratten (1970)
    Springer
    Cell & tissue research 109 (1970), S. 384-397 
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    ISSN: 1432-0878
    Keywords: Heart muscle cells ; Electron microscopy ; Quantitative ; Asphyxia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Normale und hypoxische Herzmuskelzellen aus der Wand des linken Ventrikels der Ratte wurden quantitativ-morphologisch anhand von elektronenmikroskopischen Längsschnitten nach Perfusionsfixierung untersucht. In normalen Zellen waren alle Myofibrillen relaxiert, die mittlere Sarcomerlänge betrug 2,2 μm. Die Schnittfläche wurde zu 55% von Myofibrillen, zu 27% von Mitochondrien und zu 18% von Grundplasma und Reticulum eingenommen. Die zwischen den Myofibrillen liegenden Mitochondrien waren längsoval und im Mittel 2,3mal so lang wie breit. Es bestand kein Unterschied zwischen subendokardial und subepikardial gelegenen Zellen. 10 min nach Erstickung der Tiere waren in den sonst unauffälligen Muskelzellen die Glycogengranula vermindert. Nach 20 min führte die Hypoxie zu einer Zunahme der relativen Schnittfläche der Mitochondrien um etwa 16% und zu einer beginnenden Kontraktur der Myofibrillen (Sarcomerlänge 2,0 μm). 20 min Hypoxie in Hypothermie (25–30°C intrathorakal) veränderte die normale Zellstruktur dagegen kaum. Wenn die Herzen während der 20 min dauernden Hypoxie in Normothermie mit einer procainhaltigen sauerstoff- und glucosefreien Blutersatzlösung durchspült wurden, waren die Myofibrillen relaxiert, die Schwellung der Mitochondrien dagegen wurde nicht reduziert. 30 min nach Erstickung wurde die Kontraktur stärker (Sarcomerlänge 1,7 μm). Nach 60 min bildeten sich Superkontraktionsknoten, einzelne Myofibrillen waren in Höhe der I-Bänder unterbrochen. Die Cristae der Mitochondrien wichen auseinander, die Schnittfläche der Mitochondrien hatte um 27% zugenommen. Während in Normotherapie eine Asphyxie des Tieres bereits nach 10 min die Herzmuskelzellen funktionell schwer schädigt, ist die Schädigung morphologisch erst nach 20 min eindeutig. Das bedeutet, daß für die elektronenmikroskopische Präparation eine Hypoxie von unter 10 min bedeutungslos ist. Hinsichtlich der morphologischen Manifestationszeit für die Unterbrechung der Sauerstoffversorgung stimmen unsere Befunde an Herzmuskelzellen gut mit vergleichbaren Angaben an Leberzellen überein.
    Notes: Summary In heart muscle cells of the left ventricle of rats the distribution of cell organelles and their reaction to hypoxia were investigated by electron microscopy. In normal hearts fixed by perfusion with aldehydes, the mean sarcomere length was 2.2 μm. 27% of the longitudinal sectional area was occupied by mitochondria, 55% by myofibrils and 18% by sarcoplasmic reticulum and ground plasm. The mitochondria situated in rows between the fibrils were oval and measured 2.3 times more in length than in width. There was no difference between cells from subendocardial and subepicardial regions. 10 min hypoxia (complete occlusion of the trachea) did not affect the appearance of muscle cells but diminished the number of glycogen granules. After 20 minutes the area occupied by mitochondria was increased by 16%, the mitochondria between the myofibrils were more spherical and only 1.5 times longer than wide. The sarcomeres shortened to 2.0 μm. With hypothermia (25–30°C) hypoxia of 20 minutes duration did not affect the cell structure. Perfusion of the heart by a saline solution, which contained procaine but neither oxygen nor glucose, for 20 minutes prevented shortening of the sarcomeres but not swelling of the mitochondria. 30 minutes after occlusion of the trachea the myofibrils shortened to a sarcomere length of 1.7 μm. After 60 minutes irregularly and excessively contracted myofibrils appeared and some sarcomeres were interrupted at the level of the I-bands. In some of the swollen mitochondria the cristae were widely separated. The increase of the area occupied by mitochondria was 27%. Asphyxia affects heart muscle cells severely with respect to function within 10 min, but morphologically it takes 20 min before a definite effect can be noticed. As to the time after which lack of oxygen is manifested morphologically, our results are consistent with findings in liver cells.
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    Morphology of superficial postnatal cerebral cortex with special reference to synapses (1970)
    Springer
    Cell & tissue research 110 (1970), S. 540-558 
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    ISSN: 1432-0878
    Keywords: Cerebral cortex ; Synapses ; Rat ; Postnatal differentiation ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of layers I and II of the motor cerebral cortex of rat brain has been studied at birth, 4, 7 and 14 days postnatal and in the adult. Compared with the adult, neonatal rat motor cortex exhibited a large extracellular space which decreases with increasing age. At all stages studied the neurons were seen to contain the organelles usually found in adult neurons. Growth cones were present in decreasing numbers up to 14 days old. Synapses were detectable at birth and there was an obvious increase in their number throughout the postnatal development. At the earliest stages studied there was a lack of specialization characteristic of the adult. Many synapses were either avesicular or relatively so and lacked the high degree of modification of adult pre- and postsynaptic membranes. By 7 days after birth many synapses existed which in all morphological respects resembled those of the adult, and by 14 days, the majority were of the adult type. These findings, particularly with reference to the postnatal development of synapses, have been discussed in relation to the known electrophysiological findings.
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    Licht- und elektronenmikroskopische Untersuchungen über die Reversibilität von Kernmembranschrumpfungen des Ependyms im Hypothalamus der Ratte, hervorgerufen durch langdauernde Thiobarbiturat-Narkose (1971)
    Springer
    Cell & tissue research 112 (1971), S. 542-550 
    Details
    ISSN: 1432-0878
    Keywords: Ependyma ; Thiobarbiturate narcosis ; Cell nucleus shrinkage ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Im Ependym des Hypothalamus wurde das Verhalten der Zellkern-Membran nach ausgedehnter intraperitonealer Thiobarbiturat-Narkose untersucht. Die Kernmembran ist gefaltet, der Zellkern zeigt Zeichen von Schrumpfung. Diese Veränderung ist reversibel und wird nicht von der mit der Narkose verbundenen Entwässerung verursacht. Elektronenmikroskopische Untersuchungen lassen einen normalen Stoffwechsel vermuten, Zeichen von Pyknose fehlen.
    Notes: Summary Effects on the nuclear membrane were investigated in hypothalamic ependymal cells of the rat during prolonged intraperitoneal thiobarbiturate narcosis. The nuclear membrane of the nucleus was folded and the nucleus showed signs of shrinkage. These alterations were reversible and did not depend on the dehydration which developed during the narcosis. Ultrastructural signs and the absence of pyknosis suggested that metabolism during nuclear shrinkage may be normal.
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    Ultrastructural observations on the postnatal development of the rat prostate (1971)
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    Cell & tissue research 113 (1971), S. 157-173 
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    ISSN: 1432-0878
    Keywords: Prostate ; Development ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The postnatal development of the rat prostate has been studied with the electron microscope. Major developmental changes begin during the second week after birth and involve organelles associated with the formation of secretions. The amount of granular endoplasmic reticulum and the size of the Golgi complex increase greatly. Large vacuoles that probably contain secretory material are formed, and the lumen of the prostatic acini appears to contain secreted material. Large lysosomes with polymorphic interiors are present as early as 10 days after birth, and they become numerous by the end of the third week. Differences in fine structure between the different lobes of the prostate are detectable in 10–14 day old rats. The subsequent differentiation of the granular endoplasmic reticulum into the forms characteristic of the different prostatic lobes is described. The initial changes in the prostate occur in advance of sexual maturity of the animal, and the adult appearance of the gland is attained by 4–5 weeks after birth.
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    An ultrastructural study of the neurosecretory cells of the medial vascular prechiasmatic gland, the preoptic recess and the anterior part of the suprachiasmatic area (1971)
    Springer
    Cell & tissue research 114 (1971), S. 404-440 
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    ISSN: 1432-0878
    Keywords: Neurosecretory cells ; Rat ; Cytoplasmic bodies resembling nucleoli ; Paranucleolar and coiled bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A distinctive cytoplasmic inclusion, termed nucleolus-resembling body, was identified in the neurons, but not in the glial cells, of the medial vascular prechiasmatic gland, the preoptic recess and the anterior part of the suprachiasmatic area in the rat. This ultrastructure which lacks a limiting membrane is made of an entanglement of tightly packed filaments, 60–70 Å in diameter. Each filament consists of smaller units, 15–20 Å thick. Usually, only one such ultrastructure is present in a cell, but at time two were identified. It is present in most neurosecretory cells. It is surrounded by polyribosomes in the perikaryon of the nerve cells. Furthermore, it is linked to peripherally located ribosomes by means of filaments, 70 Å in diameter. A possible function in protein synthesis of structural components, such as neurofilaments, is hypothesized. Two distinctive fibrillar areas were identified in the nucleolus according to the tightness with which fibrils were packed together. Their significance is discussed. Nucleolar extrusions were never observed in our studies. Paranucleolar and coiled bodies were identified in the nuclear sap. The mechanism of formation and the significance of these bodies are discussed.
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    Histotypic organization of the rat retina in vitro (1971)
    Springer
    Cell & tissue research 114 (1971), S. 557-579 
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    ISSN: 1432-0878
    Keywords: Retina ; Tissue Culture ; Synapses ; Retinal Rods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Netzhäute von 2–3 Tage alten Ratten wurden in Plasma auf Deckgläsern in Rollerröhrchen zur Kultur angesetzt. Nach 7–17 Tagen in vitro wurden die Kulturen mit Aldehyden und Osmiumsäure fixiert und für elektronenmikroskopische Untersuchung weiterverarbeitet. Gewebsquerschnitte (senkrecht zum Deckglas) zeigten histotypische Organisation, besonders in den dickeren Abschnitten der Explantate. Die Schichtung der Zellen entwickelte sich ganz ähnlich derjenigen in der Retina in situ aus dem relativ primitiven ausgepflanzten Netzhautepithel, jedoch enthielten die verschiedenen Schichten weniger Zellen als in der Retina in vivo. Alle Hauptnervenzelltypen konnten auf Grund ihrer Lokalisation und ihrer cytologischen Merkmale unterschieden werden. Die Entstehung von membranösen Lamellen in den Außengliedern der Sinneszellen konnte als Einfaltung der Plasmamembran beobachtet werden. Synaptische Bandkomplexe in ausgereifter Form wurden in der äußeren plexiformen Schicht nachgewiesen, während konventionelle Synapsen in der inneren plexiformen Schicht häufig angetroffen wurden. Synaptische Bänder waren ebenfalls in den Axonen bipolarer Zellen in der inneren plexiformen Schicht nachweisbar. Amakrine und Ganglienzellen waren in diesen Regionen ziemlich selten vertreten. Da die Untersuchung von nicht kultivierten Netzhäuten drei Tage alter Tiere keinerlei Synapsen zeigte, wird geschlossen, daß die Synapsen in den Kulturen in vitro entstanden sein müssen. Die Netzhaut stellt ein günstiges Modell für die Synaptogenese in vitro dar, indem sie verschiedene Vorzüge vor Explantaten aus anderen Regionen des Zentralnervensystems aufweist, nämlich eine klare Schichtung, zahlreiche identifizierbare Zellfortsätze mit charakteristischen synaptischen Beziehungen und eine wohl definierte Folge von Entwicklungsvorgängen.
    Notes: Summary Retinae from two- and three-day-old rats were explanted in plasma clots and grown in vitro with the flying coverslip method. After seven to seventeen days in culture, the retinal tissue was fixed with aldehydes and osmium tetroxide and embedded for examination with the electron microscope. Study of cross sections (perpendicular to the coverslip) revealed a histotypic pattern of organization, especially in the thicker regions of the explants. Layering of cells quite similar to that in the intact retina was seen to develop from the relatively primitive, explanted retinal epithelium. However, each layer contained fewer cells than its counterpart in vivo. All major neuronal cell types were distinguished by their location and cytological characteristics. Development of the saccules of sensory cell outer segments was observed to occur in vitro by an infolding of the plasma membrane. Synaptic ribbon complexes developed to the mature form in the outer plexiform layers, while conventional synapses were numerous in the inner plexiform layers. Synaptic ribbons were also seen in bipolar cell axons in the inner plexiform layers. Amacrine and ganglion cells in these regions were relatively sparse. A survey of posterior regions of noncultured three-day-old rat retinae showed no synapses of any sort; therefore the synapses in the cultures formed in vitro. The retina is recommended for studies of synaptogenesis in tissue culture, for it offers several advantages over expiants from other areas of the neuraxis, including a clear layering pattern, many identifiable cell processes with characteristic synaptic relationships between them, and a well-defined sequence of developmental events.
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    Long-term trophic effect of ACTH on rat adrenocortical cells (1971)
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    Cell & tissue research 115 (1971), S. 30-45 
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    ISSN: 1432-0878
    Keywords: Adrenal Cortex ; ACTH ; Autoradiography ; Stereology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The changes occurring in rat adrenocortical cells (zona fasciculata) during an 8 day period of treatment with ACTH, were investigated by morphometric and autoradiographic methods. The most important ultrastructural change consists in a conspicuous increase in the smooth endoplasmic reticulum, that accounts for about 50% of the total increase of cellular volume. Also the mitochondrial fraction shows a significant increase, which is found to be due both to the increment in the number of mitochondria per cell and to the increase in the mean volume of organelles themselves. The quantitative autoradiographic data, indicating an increment in the incorporation of 3H-orotate and 3H-leucine into adrenocortical cells of the treated animals, allow us to conclude that the ACTH-induced ultrastructural changes are the morphological expression of a stimulation of the cellular protein synthesis. Since mitochondria are largely autonomous in the synthesis of their enzymes and structural proteins, it is possible to hypothesize that ACTH also intervenes in the regulation of the mitochondrial protein synthesis.
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    Sur l'existence de cellules de type ≪corticotrope≫ dans la pars intermedia de l'hypophyse du rat (1971)
    Springer
    Cell & tissue research 115 (1971), S. 60-68 
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    ISSN: 1432-0878
    Keywords: Adenohypophysis ; Pars intermedia ; Corticotrophic cells ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Nos observations démontrent l'existence de deux types de cellules glandulaires dans la pars intermedia de l'hypophyse du rat: des cellules propres, à M.S.H., dont les grains de sécrétion sont détruits par la fixation osmiée et relativement bien conservés par la fixation au glutaraldéhyde; des cellules à petits grains denses, osmio-résistants, qui s'apparentent morphologiquement aux éléments corticotropes de l'antéhypophyse. L'existence bien connue d'A.C.T.H. ou, plus précisément, d'un facteur ≪A.C.T.H.-like≫ dans le lobe neuro-intermédiaire nous fait considérer comme très vraisemblable la nature corticotrope de ce deuxième type cellulaire de la pars intermedia.
    Notes: Summary Two types of glandular cells have been shown to occur in the intermediate lobe of the rat hypophysis: 1) M.S.H. producing cells whose secretory granules are destroyed by osmium fixation and relatively well preserved by glutaraldehyde fixation, 2) cells with small dense osmium resistant granules being morphologically similar to the corticotrophic cells of the anterior lobe. The well known occurrence of A.C.T.H. or, more precisely, of an “A.C.T.H.-like” factor in the neuro-intermediate lobe makes the corticotrophic nature of this second cell type very likely.
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    Neurofilaments and microtubules in sensory neurons after peripheral nerve section (1971)
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    Cell & tissue research 117 (1971), S. 191-211 
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    ISSN: 1432-0878
    Keywords: Sensory neurons ; Rat ; Nerve section ; Neurofilaments ; Neurofibrils
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sensory neurons were examined in spinal ganglia of the rat 1 to 55 days after section of the plexus brachialis nerves. Only “light” neurons of the type A were investigated. Maximal reaction to axotomy was found 7 to 14 days after the operation. The majority of the axotomized perikarya developed central chromatolysis. In such neurons, Nissl bodies virtually disappeared from the central area of the neuron and formed a more or less continuous zone at the cell circumference. The cytocentrum became filled with large numbers of mitochondria, dense bodies and other organelles. Neurofilaments and microtubules were disarranged and ran at random among the accumulated particles. Microtubules were often more prominent in chromatolytic areas than neurofilaments. Both these organelles were rare in the peripheral areas filled with massed Nissl substance. Part of the neurons that did not show typical chromatolysis contained increased numbers of neurofilaments among Nissl bodies dispersed throughout the cytoplasm. Neurofilaments were roughly arrayed in bundles up to several microns wide; they were linked by cross-bridges and separated by distances of about 500 Å. Microtubules were rarely found in the filamentous areas. However, they were numerous in the axon hillock and in the initial segment where they formed fascicles similar to those described in normal neurons of other types. During the period from 14 to 55 days after axotomy, many perikarya recovering from chromatolysis contained enlarged bundles of neurofilaments with occasional microtubules among the restored Nissl bodies. Mean diameters of sensory neurons, measured 7 to 55 days after axotomy, in no instance exceeded those of contralateral control neurons. It thus appears that sensory perikarya do not increase in size either during the chromatolytic process or during the period of recovery.
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    Geschlechtsunterschiede in der Ultrastruktur der Nebennierenrinde der Ratte (1971)
    Springer
    Cell & tissue research 116 (1971), S. 136-150 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Sex difference ; ACTH ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Nebennierenrinde von 178 Sprague-Dawley-Ratten wurde elektronenmikroskopisch von der 1.–12. Lebenswoche unter Normalbedingungen sowie nach s.c. Injektion von 3 IE ACTH/100 g Körpergewicht innerhalb von 2 min — 24 Std untersucht. Ab der 5. Lebenswoche unterscheiden sich die Nebennieren von Weibchen im Bereich der äußeren Zona fasciculata durch Kernvergrößerung, größere Mitochondrien und kleindisperse Liposomen von denen der Männchen. Zyklusbedingte Schwankungen in der Ultrastruktur der weiblichen Nebennierenrinde bestehen nicht. Nach ACTH-Applikation nähert sich das Nebennierenbild des Männchen innerhalb von 30 min dem des unbehandelten Weibchens. Außerdem kommt es bei beiden Geschlechtern durch ACTH zu einer Dispersion und Reduktion der Liposomen, Vergrößerung des Golgiapparates und der Zellkerne, Ausweitung des endoplasmatischen Retikulums und Vermehrung der Mikrovilli. Der Geschlechtsdimorphismus wird funktionell erklärt.
    Notes: Summary 178 Sprague-Dawley-rats were studied by electron microscopy from the 1st to the 12th week of life under normal conditions and after s. c. injection of 3 I. U. ACTH/100 gbodyweight from 2 min to 24 hours. Beginning with the 5th week of life females differ from males by small dispersed liposomes and enlarged nuclei and mitochondria in the outer z. fasciculata. There is no change in the ultrastructure of the female adrenal cortex depending on the sexual cycle. After application of ACTH the adrenal cortex of males assimilates to the untreated females within 30 min. After ACTH-application both sexes show dispersion and reduction of liposomes, dilation of endoplasmatic reticulum, increasement of microvilli and enlargement of the Golgi apparatus. The sex-dimorphism is interpreted by functional differences.
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    Wachstumsverhältnisse des Samenblasenepithels bei der heranwachsenden weißen Ratte (1971)
    Springer
    Cell & tissue research 119 (1971), S. 378-383 
    Details
    ISSN: 1432-0878
    Keywords: Seminal vesicles ; Rat ; Epithelium ; Proliferation activity ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung An 12 männlichen weißen Wistarratten unterschiedlichen Alters wurde autoradiographisch die Proliferation des Samenblasenepithels zur Zeit der Pubertät geprüft. Die Tiere waren 21, 29, 40, 50, 60 und 180 Tage alt und erhielten 1 Std vor der Tötung durch Dekapitation 2,5 μC 3H-Thymidin/g Körpergewicht i. p. appliziert. Ausgewertet wurden Autoradiogramme nach einer Expositionszeit von 18 Tagen; bestimmt wurde der Prozentsatz der markierten Zellkerne (3H-Index). Im Gegensatz zu dem bekannten exponentiellen Abfall des 3H-Indexes bei nicht-hormonabhängigen Leberepithelien jugendlicher Ratten kommt es beim Epithel der Samenblasen um den 40. Lebenstag zu einem erneuten, starken Proliferationsschub. Diese starke Wachstumszunahme ist wahrscheinlich der proliferationskinetische Ausdruck der nach Steinberger (1970) zur gleichen Zeit stattfindenden hormonellen Umschaltung in den Testes. Anschließend geht das Vermehrungswachstum des jugendlichen Tieres, durch das die Zellzahl erhöht wird, in das Erhaltungswachstum über; der 3H-Index des Samenblasenepithels erreicht den Wert des erwachsenen Tieres.
    Notes: Summary In 12 male white rats (Wistar) the proliferative activity of the epithelial cells in the seminal vesicles was studied by autoradiography. The animals were 21, 29, 40, 50, 60 and 180 days old. Each animal was given 2.5 μC/g 3H-thymidine and was killed 1 hour thereafter. We analysed the autoradiograms recording the percentage of labelled nuclei (3H-index). While the 3H-index of the non hormone-dependent epithelial cells in the liver of young rats declines continously with growing age (Stocker et al., 1964), the epithelial cells in the seminal vesicles of 40 days old rats show a remarkable rise in their proliferative activity. It is quite possible that this new peak in the proliferation is the morphological result of a preceeding switch in hormonal production of the testes as reported by Steinberger (1970). Thereafter the growth proliferation of the young rats declines into the steady state of the grown up.
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    Beitrag zur Kenntnis der Glomera coronaria der Katze (1971)
    Springer
    Cell & tissue research 118 (1971), S. 532-554 
    Details
    ISSN: 1432-0878
    Keywords: Glomera coronaria ; Cat ; Chemoreceptor cell ; Blood supply ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Gefäße der zwischen Aorta ascendens und Truncus pulmonalis, an der Vorder- und Hinterwand des Truncus pulmonalis gelegenen Glomera, sowie das sogenannte „Glomus pulmonale“ der Katze lassen sich von den Coronararterien aus durch Tusche-Gelatine-Lösungen füllen. Die erwähnten Paraganglien sind als Chemoreceptorenfelder dem Coronarkreislauf angeschlossen und daher als Glomera coronaria zu bezeichnen. Licht- und elektronenmikroskopische Untersuchungen ergaben eine morphologische Übereinstimmung mit dem Glomus caroticum. Vagusdurchtrennungen verursachen eine Degeneration der an den Glomuszellen gelegenen synaptischen Formationen sowie Veränderungen in Glomuszellen.
    Notes: Summary The vessels of the glomera that lie between the aorta and the pulmonary trunk, on the anterior and posterior wall of the pulmonary trunk, as well as the so-called glomus pulmonale of the cat have been injected with gelatine-india ink mixture. The paraganglia mentioned above are associated with the coronary circulation as chemoreceptors and are designated as the glomera coronaria. The investigations demonstrate a morphologic similarity with the glomus caroticum. Section of the vagus causes a degeneration of the synaptic structures on the glomus cells as well as changes in the cells themselves.
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    URL: http://dx.doi.org/10.1007/BF00324619
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    Untersuchungen zur Fettresorption im Dünndarm der Ratte, unter besonderer Berücksichtigung der Tagesrhythmik (1971)
    Springer
    Cell & tissue research 119 (1971), S. 334-354 
    Details
    ISSN: 1432-0878
    Keywords: Fat absorption ; Small intestine ; Rat ; Micropinocytosis ; Circadian rhythm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die vorliegende Untersuchung will klären, welche Rolle die Mikropinocytose bei der Fettresorption spielt und ob die Fettresorption tagesrhythmische Schwankungen aufweist. Zu diesem Zweck wurde Fett zu verschiedenen Tages- und Nachtzeiten in abgebundene Jejunumabschnitte von Ratten injiziert, das Darmgewebe in verschiedenen Abständen licht- und elektronenmikroskopisch untersucht und die Zahl der mikropinocytotischen Invaginationen der Enterocyten bestimmt. Folgende Resultate wurden erzielt: Die Häufigkeit der Mikropinocytose (mikropinocytotische Invaginationen/100 Mikrovilli) beträgt bei Hungertieren 4,78, bei Normaltieren 5,06, 1 min nach Gabe von Mazolachymus 3,55, 1/16 m NaCl-Lösung 4,37, Butterschmalz 5,50, Rindertalg 7,16, Schweineschmalz 7,66 und Mazola 9,25; 2 1/2 min nach Mazolagabe 8,23, nach 5 min 7,67, nach 10 min 6,76. Zwischen 10 und 15 min wird der Ausgangswert erreicht. Aufgrund statistischer Auswertung der Befunde wird geschlossen, daß Fett vor allem in den Frühstadien der Fettresorption durch Mikropinocytose aufgenommen werden könnte. Ferner zeigt sich, daß die Mikropinocytosehäufigkeit entscheidend von der chemischen Zusammensetzung und dem physikalischchemischen Zustand der verabreichten Fette beeinflußt werden dürfte. — Lichtmikroskopisch wurde nachgewiesen, daß die Fettresorption charakteristische, tagesrhythmische Schwankungen aufweist. Um 2.00 Uhr ist sie am stärksten, um 14.00 Uhr am geringsten. Es wird diskutiert, worauf die tagesrhythmischen Unterschiede zurückzuführen sind.
    Notes: Summary The present study attempts to elucidate (a) to what extent micropinocytosis is involved in the process of fat absorption and (b) whether fat absorption shows a circadian rhythm. For this purpose rats were given 0.1 to 0.15 ml of fat directly into the upper jejunum at various times of the day and night. 20 sec to 20 min after administration of fat small pieces of the jejunum were rapidly dissected out, the tissue examined by means of light- and electron microscopy, and the number of micropinocytotic pits occurring in the enterocytes during fat absorption was determined. The following results were obtained: The frequency of micropinocytosis (micropinocytotic pits/100 microvilli) is as follows: in starved rats 4.78, in normal rats 5.06, 1 min after administration of corn oil chyme 3.55, 1/16 m NaCl-solution 4.37, clarified butter 5.50, ox tallow 7.16, lard 7.66, corn oil 9.25; 2 1/2 min after administration of corn oil 8.23, after 5 min 7.67, and after 10 min 6.76. Between 10 and 15 min the number of micropinocytotic pits reverses to normal. From statistical analysis of the results it is concluded that micropinocytosis can play a significant role in the early stages of fat absorption. The experiments show in addition that micropinocytosis is greatly influenced by the chemical composition and the physico-chemical state of the administered fat.—Light microscopic studies indicate that fat absorption varies considerably during the 24 hr period. The highest absorption was found at 2 a.m., the lowest at 2 p.m.
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    The manchette in Stage 14 rat spermatids: A possible structural relationship with the redundant nuclear envelope (1972)
    Springer
    Cell & tissue research 124 (1972), S. 1-11 
    Details
    ISSN: 1432-0878
    Keywords: Spermiogenesis ; Rat ; Spermatids ; Manchette ; Microtubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The manchette or caudal tube has been examined in Stage 14 rat spermatids. The microtubules of the caudal tube have been found to be partially sheathed by smooth endoplasmic reticulum which appears to be continuous with the outer nuclear membrane of the redundant nuclear envelope. The microtubules in caudal regions of the manchette have been noted to be interconnected by links of unusual size and morphology. It is suggested that the caudal tube consists at this stage of development of two structures, membrane and microtubules and that the links between the microtubules appear to play a role in the structural order noted in the position of the tubules of the manchette. The possible significance of these links in relation to motility is discussed.
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    URL: http://dx.doi.org/10.1007/BF00981937
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    Ultrastructural study of neurovascular contacts in the median eminence of the rat (1972)
    Springer
    Cell & tissue research 124 (1972), S. 311-319 
    Details
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Neurovascular contacts ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the median eminence of the rat axons of the supraoptic-paraventricular-hypophyseal tract with elementary neurosecretory granules (150–200 mμ) traverse the internal zone. Terminals containing dense core vesicles 60–120 mμ in diameter end on the portal capillaries of the median eminence. A unique organisation of the primary portal capillaries is shown. Endothelial cells have many fenestrae. The pericapillary space has numerous extensions all of which represent a special zone around the endothelial tube. The fine structural organisation and function of the neurovascular contacts in the median eminence are discussed.
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    Pituitaries of rats neonatally treated with oestrogen (1972)
    Springer
    Cell & tissue research 126 (1972), S. 41-52 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary ; Rat ; Oestradiol influence ; STH-cells ; Leucine incorporation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pituitaries of male and female rats neonatally treated with oestradiol dipropionate were examined with light and electron microscopy, disc electrophoresis and in vitro C14-leucine incorporation. Single dose of oestradiol administered shortly after birth to male rats has an prolonged stimulative effect on LTH synthesis and release. This is expressed in the cell hypertrophy, proliferation of ER, increase of corresponding band density and higher rate of 14C-leucine incorporation. In females this effect was less pronounced. STH cell in the treated male pituitaries were degranulated, corresponding hormone band density significantly lowered and incorporation of 14C-leucine was reduced. This could be considered as an inhibitory effect of oestradiol on STH synthesis and release. Such effect was more expressed two than four months after treatment and is more pronounced in male than in female rats.
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  • 84
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    Autoradiographische Untersuchungen zum Wachstum der Nebennierenrinde der Ratte (1972)
    Springer
    Cell & tissue research 126 (1972), S. 421-430 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Growth ; Sex-dimorphism ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Anhand des Verlaufs des 3H-Index und der Mitoserate in Anhängigkeit vom Lebensalter wurde die Proliferationsaktivität in den Zonen der Nebennierenrinde untersucht. 84 SPF-Ratten erhielten 2 μCi/g 3H-Thymidin i.p.; der Untersuchungszeitraum erstreckte sich vom 18. Trächtigkeitstag bis zur 12. Lebenswoche. Alle Zonen zeigten in der Rangfolge Glomerulosa — Fasciculata — Reticularis eine Abnahme DNS-synthetisierender Zellkerne. Geschlechtsspezifische Unterschiede im Ausmaß der Proliferationsaktivität konnten zu keiner Zeit nachgewiesen werden. Aus der Dissoziation der Kurven des 3H-Index und der Mitoserate bei vergleichbaren DNS-Syntheseraten wird auf eine Änderung der G2-Phase des Generationszyklus der NNR-Zellen in der teilexponentiellen Wachstumsphase geschlossen.
    Notes: Summary In 84 SPF-rats the poliferative activity of the adrenal cortical cells was studied from the 18th day of pregnancy up to 12 weeks post partum. Rats were given 2 μC/g tritiated thymidine and killed 1 hour thereafter. It was shown that there was no sex-related difference in the degree of proliferation that could explain the sexual dimorphism in adrenal weights. In all cortical zones a decrease in the number of labeled cells was seen during the obvservation period. The highest percentage of labeled cells was found in the glomerulosa. There exists no parallelism of the mitotic and labeling index, which gives evidence for a change in length of the G2-phase of the cell generation cycle.
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    Innervation and vascular supply of the crayfish opener muscle: Scanning and transmission electron microscopy (1972)
    Springer
    Cell & tissue research 127 (1972), S. 189-200 
    Details
    ISSN: 1432-0878
    Keywords: Crustacean ; Muscle ; Nerve ; Blood vessel ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were employed to study the innervation and vascular supply of crayfish skeletal muscle. Blood vessels and nerve terminals identified by TEM were often closely associated. Synaptic regions of the nerve terminals were always located under sarcolemma and contained both dense-cored and agranular synaptic vesicles. Axo-axonal synapses of several different types were observed. Blood vessels consisted of several “vessel cells” or “supporting cells” enclosing a lumen, which was connected to the exterior by fine channels between the “supporting cells”. SEM of whole freeze-dried muscles revealed two types of ramifying structure, which often ran in parallel over the muscle surface. One, identified as nerve, was more cylindrical and had a smoother surface than the other, which was identified as blood vessel. Fine nerve branches disappeared under the sarcolemma, probably near synaptic regions, but synapses could not be seen. Blood vessels also had fine terminations which merged into the sarcolemma.
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    Ultrastructural features of the lateral preoptic area, median eminence and arcuate nucleus of the rat (1972)
    Springer
    Cell & tissue research 127 (1972), S. 483-491 
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    ISSN: 1432-0878
    Keywords: Lateral preoptic area ; Hypothalamus ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The arcuate nucleus, median eminence, and the lateral preoptic area from the brains of aldehyde-perfused male and female rats were examined by electron microscopy. In the lateral preoptic area, three neuronal types are described: a small light neuron, a larger light one, and a dark neuron resembling the larger light one in size and nuclear shape. Many myelinated axons are interposed among single neurons or neuronal pairs. The relationship of structures to each other is discussed. Several observations not previously reported are illustrated from tissue of the arcuate nucleus and median eminence.
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    Distribution of monoamine oxidase in the hippocampal region of the rat (1972)
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    Cell & tissue research 124 (1972), S. 354-366 
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    ISSN: 1432-0878
    Keywords: Hippocampal region ; Rat ; Monoamine oxidase ; Chemoarchitectonics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. The distribution of monoamine oxidase (MAO) in the hippocampal region of the rat has been studied in cryostat sections with the tryptamine-tetrazolium method of Glenner et al. 2. The staining pattern was rather diffuse as compared with the distribution of MAO in the guinea pig and of other enzymes in the rat hippocampal region. 3. However, there were differences in enzyme activity between different areas and layers which could be correlated to some degree with results obtained with other methods, e.g., silver impregnation, catecholamines, and acetylcholinesterase.
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    Monoamines in rat thyroid parafollicular cells and the effect of vitamin D2-induced degranulation (1972)
    Springer
    Cell & tissue research 128 (1972), S. 406-425 
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    ISSN: 1432-0878
    Keywords: Parafollicular Cells ; Rat ; Normalcalcemia ; Vitamin D2 ; Electronmicroscopy ; Histochemical fluorescence method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thyroid parafollicular cells of normocalcemic and vitamin D2-treated rats were investigated by electron microscopy and with the histochemical fluorescence technique of Hillarp and Falck. Administration of high doses of vitamin D2 caused hypercalcemia and an extensive degranulation of the parafollicular cells. The formation and storage of monoamines in granulated and degranulated parafollicular cells was investigated by fluorescence microscopy after injection of monoamine precursors (DOPA, 5-HTP), alone or in combination with Ro 4-4602, nialamide or reserpine. No fluorescence was observed in parafollicular cells of untreated rats. l-DOPA and l-5-HTP (but not the corresponding D-amino acids) were taken up by a process closely linked to the decarboxylation of the amino acids to the corresponding amines (dopamine and 5-hydroxytryptamine). Treatment with vitamin D2 did not seem to affect the formation of amines in the parafollicular cells or the formation and storage of amines in other cell systems investigated. The amine itself (dopamine) was not taken up by the parafollicular cells. In normocalcemic rats, the amine formed was retained in the cytoplasm of the parafollicular cells by a partially reserpine-resistant mechanism. The storage of amines is concluded to occur in association with the calcitonin-containing granules. In parafollicular cells of vitamin D2-treated rats, a certain amount of amine was bound in the cytoplasm in the absence of typical granules. As a considerable amount of calcitonin is known to remain in the thyroid of vitamin D2-treated rats, the present observations may indicate an association between the amine and the polypeptide hormone calcitonin, whether the latter is confined to typical granules or not.
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    Electron microscope study of the myofibril partial disintegration and recovery in the mitotically dividing cardiac muscle cells (1972)
    Springer
    Cell & tissue research 129 (1972), S. 471-499 
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    ISSN: 1432-0878
    Keywords: Cardiac muscle cells ; Rat ; Mitotic division ; Myofibril changes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the myocyte at all phases of mitosis as well as of early postmitotic cells has been studied in the myocardia of 14- and 18-day rat embryos and 5- and 7-day old rats. The myofibrils remain unchanged up to the late prophase. In prometaphase the majority of Z-disks in embryo myocyte myofibrils and considerable part of these disks in myofibrils of suckling rats are drastically disintegrated. This is followed by a progressive isolation and scattering of the myofilament bundles and of the whole sarcomeres during the subsequent phases of mitosis. Thick myofilaments seem to be unchanged but thin ones become frequently poorly outlined (mainly in embryos). The sarcoplasmic reticulum, including its typically differentiated subsarcolemmal cisternae, exhibits relatively few changes during mitosis. In the early postmitotic period there is a gradual restoration of contrast-rich Z-bands, interconnecting the previously isolated sarcomeres. Patterns of this process have much in common with early stages of myofibrillogenesis (appearance of subsarcolemmal “Z-bodies”, formation of skeins of thin filaments etc.). The cleavage furrow formation is either absent or considerably retarded up to the postmitotic period. Behaviour of some other organelles during myocyte mitosis has been described. Possible mechanisms and significance of the observed phenomena are discussed.
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    Zur Ultrastruktur der Gefäßfortsätze von Ependymund Gliazellen im Infundibulum der Ratte (1972)
    Springer
    Cell & tissue research 130 (1972), S. 58-69 
    Details
    ISSN: 1432-0878
    Keywords: Infundibulum ; Rat ; Ependymal and glial cells ; Inclusions ; Neuroglial synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Zahlreiche Ependymzellen des Recessus infundibularis und Gliazellen der Zona externa besitzen Fortsätze, die bis an den perivaskulären Raum der Kapillarschlingen des Portalplexus heranreichen. Die Ultrastruktur dieser Gefäßfortsätze wird beschrieben. Sie können verschiedenartige Einschlüsse enthalten: 1. große, runde osmiophile Einschlüsse (0,5–2 μ im Durchmesser), die als „lipid inclusions“ bezeichnet werden; 2. unregelmäßig geformte, granuläre Einschlüsse mit gleichmäßiger Elektronendichte (500 bis 2000 Å im Durchmesser); 3. rundliche Granula mit einem hellen Zentrum und ringartig um dieses Zentrum gelagerten elektronendichten Körnchen (1200–1600 Å im Durchmesser). Der letztgenannte Granulatyp scheint ein charakteristisches Merkmal der Gefäßfortsätze in der Zona externa der Wistar-Ratte zu sein. Meist häufen sich die Körnchen gemeinsam mit den anderen beschriebenen Einschlüssen in den kolbenförmigen Endigungen der Gefäßfortsätze. Exocytosevorgänge an der dem perivaskulären Raum zugewandten Oberflächenmembran der Fortsätze weisen auf eine Abgabe von Substanzen an die Blutbahn hin. Neurogliöse Synapsen finden sich im Infundibulum vorwiegend zwischen Nervenfasern des Tractus tuberohypophyseus und Gefäßfortsätzen der Ependym- und Gliazellen. Der synaptische Spalt enthält häufig fädige oder körnige Strukturen. Solche Partikel finden sich zusammen mit tubulären oder vesikulären Membranprofilen auch im synapsennahen Bereich des Glia- oder Ependymfortsatzes. Die funktionelle Bedeutung dieser Synapsen insbesondere für die Abgabe neuronaler Substanzen wird diskutiert.
    Notes: Summary Many ependymal cells of the infundibular recess and many glial cells of the external layer send their processes to the perivascular space of capillary loops of the portal plexus. The ultrastructure of these vascular processes is described. They may contain various inclusions: (1) large, osmiophilic globules (0,5–2 μ in diameter), mostly termed “lipid inclusions”; (2) irregularly formed, granular inclusions with an evenly distributed content (500–2000 Å in diameter); (3) circular granules comprising an electron-lucent centre surrounded by an annular wall of electron-dense particles (1200–1600 Å in diameter). This type of granule seems to be characteristic for the vascular processes in the external layer of the Wistar rat. Frequently accumulations of these granules are found together with other inclusions in the widened end-feet of the vascular processes. The occurrence of exocytosis at the perivascular surface membrane of the vascular processes indicates a release of substances into the blood. Neuro-glial synapses in the infundibulum are mainly found between nerve fibres of the tuberohypophyseal tract and the vascular end-feet of ependymal and glial cells. The synaptic cleft often contains filamentous or granular material. Together with tubular and vesicular membrane profiles such particles are also found in the postsynaptic area of the ependymal and glial processes. The functional significance of these contacts is discussed particularly with respect to the release of neuronal substances.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306994
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    The lorenzinian ampullae of Polyodon spathula (1972)
    Springer
    Cell & tissue research 130 (1972), S. 362-377 
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    ISSN: 1432-0878
    Keywords: Lorenzinian ampullae ; Polyodon spathula ; Sensory epithelium ; Synapses ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light and electron microscopic observations on the ampullary organs of Polyodon spathula (Chondrostei, Osteichthyes) reveal a sensory epithelium similar to that found in the Lorenzinian ampulla, an electroreceptor found in marine Elasmobranchs. The sensory cells have a very small luminal part provided with a cilium. They are innervated by many nerve endings. Each nerve fibre apparently makes synaptic contact with several sensory cells. The synaptic structure in the sensory cell is composed of a flat sheet, the outermost part of which is surrounded by 3 or 4 annuli of densely staining material. The sheet extends into a protrusion of the sensory cell, and there is a corresponding invagination in the nerve terminal. The conclusion that these organs are electroreceptors, is supported by the finding that the fish responds to the introduction of an iron tube in the aquarium, whereas a wooden rod introduced in the same way causes no response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306949
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    Ultrastructure of neuromuscular junctions in Limulus heart (1972)
    Springer
    Cell & tissue research 130 (1972), S. 481-488 
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    ISSN: 1432-0878
    Keywords: Limulus heart ; Neurogenic heart ; Neuromuscular junctions ; Synapses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructural characteristics of the neuromuscular junctions were studied in the neurogenic heart of Limulus polyphemus. Several types were encountered. The first type consisted of nerve terminals which synapsed along the borders of the myocardial fibers, embedded just under the sarcolemma. A second type of terminal was ensheathed in glial cells, synapsing on the outer sarcolemmal membrane. The third, and most prevalent type of junction consisted of terminals which synapsed with arms of granular sarcoplasm, remote from the fibrillar portion of the muscle fibers. Junctional complexes of the third type were often observed near intercalated discs and were often formed by several axons synapsing with arms of sarcoplasm from several muscle fibers. The results are discussed in relation to the previously reported electrophysiological characteristics of the neuromuscular junctions.
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    URL: http://dx.doi.org/10.1007/BF00307002
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    Isolation and characterization of neurosecretory granules of the rat posterior pituitary gland (1972)
    Springer
    Cell & tissue research 129 (1972), S. 92-113 
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    ISSN: 1432-0878
    Keywords: Neurosecretion ; Neurohypophysis ; Neurosecretory granule ; Rat ; Membranes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neurosecretory granules (NSG) of rat posterior pituitary glands were prepared by differential centrifugation techniques mainly according to the procedure as described by Barer, Heller and Lederis (1963). As revealed by electron microscopy, the recovery of neurophysin and the contents of enzymes, purified NSG were obtained in a pellet at 30 000 g/60 min (0.44 M sucrose). Eighteen h after injection of (35S) cysteine into the supraoptic nucleus 60% of the recovered radioactivity in the neural lobe was found in the NSG, whereas 20% was found in the final supernatant (100 000 g/120 min). Sixteen days after injection the NSG and the final supernatant fraction contained fairly equal amount of (35S) cysteine (approximately 40%). It is suggested that after a period of intragranular maturation neurophysin is extruded into an extragranular pool of neurosecretory material. With the use of conventional polyacrylamide-gel electrophoresis it was shown that the predominating proportion of radioactivity in the NSG after a hypothalamic injection of (35S) cysteine was located within the neurophysin fraction A and in fraction B. Fraction B is suggested to be partly bound to the NSG membranes. When the NSG soluble and NSG insoluble proteins, obtained after lysis of NSG, were separated on polyacrylamide gels in the presence of sodium dodecylsulphate, the highly radioactive soluble protein was shown to consist of two components with average molecular weights of 12 300 and 14 600. Most of the proteins in the lysate were found in the NSG membranes, though less radioactive. A component with a mol.wt. of 37 000 was enriched in the membrane fraction. At longer times after isotope injection the high mol.wt. proteins, particularly those of the NSG membranes, contained increased amounts of radioactivity.
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    URL: http://dx.doi.org/10.1007/BF00307113
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    Electron microscopy of filaments in the basal part of rat kidney tubule cells, and their in situ interaction with heavy meromyosin (1972)
    Springer
    Cell & tissue research 132 (1972), S. 497-521 
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    ISSN: 1432-0878
    Keywords: Kidney ; Rat ; Actin- and myosin-like filaments ; Tubule and interstitial cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By electron microscopy, the prominent bundles of filaments occurring in the basal part of proximal and distal tubule cells and in interstitial cells of rat kidney cortex were studied in cells fixed by vascular perfusion, in glycerol-extracted cells and in glycerol-extracted cells treated with heavy meromyosin (HMM). The studies of perfusion-fixed tissue showed that the proximal tubule cells contained in their most basal part filamentous bundles oriented transversely around the tubule. The bundles consisted of trightly packed thin filaments (50–80 Å in diameter). Similar but less prominent bundles were found in distal tubule cells and in interstitial cells. The dimension of these filaments was similar to that of actin filaments and their insertion in the basal cell membrane of the tubule epithelial cells resembled the insertion of actin filaments in the cell membrane of smooth muscle cells. The studies on glycerol-extracted cells revealed that some tubule cells contained two types of filaments (60–80 Å and 130–170 Å in diameter) located side by side in the basal filamentous bundles. The dimension of the thick filaments corresponds well to the values for myosin filaments in glycerinated smooth and skeletal muscle. The studies on HMM-reacted renal tissue revealed that the thin filaments (60–80 Å) described in tubule and interstitial cells are probably actin filaments, as they formed characteristic arrowhead complexes morphologically indistinguishable from the complexes of HMM with actin filaments in smooth and striated muscle cells. Our results provide strong evidence that a two-filament contractile system, based on interaction of actin and myosin filaments, exists in renal tubule and interstitial cells. As a hypothesis it is proposed that it is changes in tonus of the basal filamentous system in the proximal tubule cells which stabilize the intratubular pressure, possibly via angiotensin.
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    URL: http://dx.doi.org/10.1007/BF00306638
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    Ultrastructure of the pseudohermaphrodite rat testis (1973)
    Springer
    Cell & tissue research 140 (1973), S. 473-479 
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    ISSN: 1432-0878
    Keywords: Testicular feminization ; Rat ; Leydig cells ; Sterility ; Androgens, Steroids ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The interstitial cells of the pseudohermaphrodite rat testis are both hypertrophic and hyperplastic. The cytoplasm is characterized by smooth endoplasmic reticulum which is abundant and variable in form. Mitochondria are numerous and large with tubular cristae and occasional inclusions. Structural features of the Leydig cells indicate potential for increased steroid synthesis. The presence of large numbers of mast cells in the intertubular area is confirmed. Small seminiferous tubules lack advanced germinal elements. Additional connective tissue and myoepithelial layers produce a thickening of the limiting membrane. Some myoepithelial cells are atypical with an electron translucent cytoplasm and nuclei with dense peripheral chromatin. No spermatogenic cells beyond the cap phase of the spermatid are observed. The cytoplasm of Sertoli cells contains large lipid droplets and degenerating germ cells.
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    URL: http://dx.doi.org/10.1007/BF00306674
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    Origine embryonnaire et différenciation sécrétoire des cellules à calcitonine (cellules C) dans la thyroïde foetale du rat (1970)
    Springer
    Cell & tissue research 106 (1970), S. 251-268 
    Details
    ISSN: 1432-0878
    Keywords: C cells ; Thyroid ; Rat ; Ultimobranchial origin ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Nos observations confirment l'origine ultimobranchiale des cellules C de la thyroïde du rat. L'évolution des corps ultimobranchiaux (C.U.B.) a été étudiée à partir du 16ème jour de gestation, stade où ils fusionnent avec l'ébauche thyroïdienne. Dès le 17ème jour, les premières cellules C se différencient dans le C.U.B. inclus dans la thyroïde. Au 18ème jour, elles sont plus nombreuses et commencent à se disperser dans les cordons thyroïdiens. La migration des cellules C est particulièrement importante au 19ème jour. A partir du 20ème jour, les signes d'activité sécrétoire s'intensifient très nettement. A la fin de la vie foetale, les cellules C sont comparables aux cellules C adultes. La differenciation des cellules parathyroïdiennes précède nettement celle des cellules C.
    Notes: Summary Our observations confirm the ultimobranchial origin of the C cells of the rat thyroid. We studied the development of the ultimobranchial body from the 16th day of pregnancy, when there is fusion with the thyroidian anlage, onwards. As early as the 17th day, the first C cells differentiate in the ultimobranchial body which is included into the thyroid. On the 18th day, they are more numerous and start to scatter throughout the thyroidian cords. The migration of the C cells is especially obvious on the 19th day. From the 20th day onwards, there is marked increase in secretory activity. At the end of the foetal life, the C cells resemble those of the adult. The differentiation of the parathyroid cells significantly precedes that of the C cells.
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    URL: http://dx.doi.org/10.1007/BF00335742
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    Morphometric classification of the neurosecretory granules in the rat pars nervosa (1973)
    Springer
    Cell & tissue research 146 (1973), S. 463-471 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretory granule ; Pars nervosa ; Rat ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of the diameters of the neurosecretory granules in the rat pars nervosa (measured from electron micrographs taken at 40 000 × ) was compared among axons by nonparametric statistical methods and the axons were classified into five groups with median granule diameters of 143, 155, 167, 180 and 193 nm. We suggested that these five axon types carried different secretory substances contained in the pars nervosa.
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    URL: http://dx.doi.org/10.1007/BF02347176
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    Somatic spines in the supraoptic nucleus of the rat hypothalamus (1974)
    Springer
    Cell & tissue research 148 (1974), S. 203-211 
    Details
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Rat ; Supraoptic nucleus ; Ultrastructure ; Somatic spines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopic studies of ultrathin serial sections of the perikarya and adjacent neuropil of neurons of the supraoptic nucleus (SON) of the adult male rat revealed varying forms of two types of somatic spines. One type forms synapses with axons passing the cell, the other, without synapses, appears to serve as a buttress or clasp for adjacent neuronal and glial processes. The synapse-bearing spines lack the usual spine apparatus but contain the flocculent substance often seen in spines. The other spines do not exhibit either of these structures. These somatic spines were also seen in Golgi impregnated preparations but the types could not be distinguished. Certain axons synapse either on a somatic spine of the perikarya or penetrate the glial sheath of the neuron and synapse, usually repeatedly, on the soma in an en passant manner.
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    URL: http://dx.doi.org/10.1007/BF00224582
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    Ultrastructure of rat pineal gland after preparation by Freeze-etching technique (1974)
    Springer
    Cell & tissue research 148 (1974), S. 371-379 
    Details
    ISSN: 1432-0878
    Keywords: Pineal gland ; Rat ; Electric coupling areas ; Freeze-etching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pineal glands of Wistar rats were fixed in glutaraldehyde and prepared by the freeze-etching technique. With regard to the form and internal structure of pineal cells this technique has revealed nothing essentially new. Synaptic ribbons are very rarely found. A regular diagonal arrangement of membrane attached particles between the Schwann cell and the axon of an autonomic nerve terminal was observed. Three types of contact areas between pineal cells are described. In the first two types, which occur more frequently, the diameter of the area varied from 1000 to 2500 Å, with irregularly aggregated membrane associated particles. The third type, larger but less frequently found, has a surface area of 0.4 μm2 and much more regularly distributed membrane associated particles (ø 88 Å). These contact areas can be considered to be electric coupling areas between pineal cells.
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    URL: http://dx.doi.org/10.1007/BF00224264
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  • 100
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    Fine structure of trypsin-dissociated rat adrenal cells (1970)
    Springer
    Cell & tissue research 107 (1970), S. 447-453 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Rat ; Trypsin-dissociation ; ACTH stimulation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron micrographs of trypsin-dissociated rat adrenal showed predominantly intact rounded cells without internal damage. The population contained cells from the glomerular, intermediary and fascicular zones with cells from the zona fasciculata predominant. The presence or absence of cells from the reticular zone could not be determined. Cells from the medullary zone were absent. The addition of adrenocorticotropic hormone (ACTH) to the cellular suspension for 2 hours produced corticosterone. However, these stimulated cells did not display any significant ultrastructural change.
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    URL: http://dx.doi.org/10.1007/BF00335433
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