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  • 1
    Electronic Resource
    Electronic Resource
    Schwann cells are not required for guidance of motor nerves in the hindlimb in Splotch mutant mouse embryos (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 311-318 
    Details
    ISSN: 1432-0568
    Keywords: Mouse ; Splotch mutant ; Schwann cells ; Axon guidance ; Peripheral nerves ; Limb innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The topogenesis of the hindlimb nerves of Splotch homozygous mutant mouse embryos was studied using light and electron microscopy. Homozygous mutants show multiple defects of neural crest-derived tissues. The defects increase along a rostro-caudal gradient. The cervical and upper thoracic segments have small spinal ganglia, and Schwann cells are associated with the spinal nerves. In the lumbo-sacral region neurulation is not complete, and the derivatives of the neural crest are missing. The lumbo-sacral nerve trunks are formed by ventral roots only. They are occasionally associated with presumptive glial cells that have migrated from the spinal cord for a short distance. Beyond the vertebral primordia, the spinal nerves are not accompanied by Schwann cells. No compartmentalization of the axons within the lumbo-sacral nerves was visible, where as Schwann cells did segment the nerve into the fascicles in brachial nerves. The lumbo-sacral plexus develops, and its branches grow into the hindlimb despite the absence of Schwann cells. On day 13.5 of gestation, the lumbo-sacral nerve trunks extend well into the distal calf. They are topographically correctly positioned. Their branches enter the muscle primordia and form contacts with their mesenchymal cells though the cutaneous branches are missing. Generally, the outgrowth of lumbo-sacral nerves is slower than in phenotypically normal littermates, whose nerves reach the foot plate at corresponding stages of development. These results demonstrate that the lumbo-sacral plexus and the topographically correct position of lumbo-sacral nerve trunks develop despite the absence of Schwann cells. Therefore Schwann cells are not necessary for the outgrowth and guidance of axons within the limb.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185979
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  • 2
    Electronic Resource
    Electronic Resource
    Comparative studies on the pre-and postterminal blood vessels in the cerebellar cortex of rhesus monkey, cat, and rat (1979)
    Springer
    Anatomy and embryology 158 (1979), S. 51-62 
    Details
    ISSN: 1432-0568
    Keywords: Cerebellar cortex ; Pre-and postterminal blood vessels ; Rhesus monkey, cat, rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the rhesus monkey, cat and rat, pial arteries give off branches which run vertically through all three layers of the cerebellar cortex. The large cortical arteries are surrounded by a perivascular space in the molecular layer. Their wall consists of several layers of smooth-muscle cells and the luminal endothelium. As the arteries reach the deeper layers of the cerebellar cortex, the number of smooth-muscle cells is reduced. In the rat, sometimes no smooth-muscle cells are detectable in the preterminal arterial vessels. If these deep arteries branch off by dichotomy of terminal vessels there occurs a gradual or complete loss of myocytes in all three species. In the cat, where cortical arteries give off branches at rightangles, there is a sphincter-like accumulation of smooth-muscle cells at the opening to the smaller branch. The postterminal vessels and veins in all species exhibit the smae mural structure found in capillaries. The wall consists only of an endothelium and occasional pericytes embedded in the basal lamina. Even the large veins which run to the pial veins show this simple mural structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315951
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  • 3
    Electronic Resource
    Electronic Resource
    Origin of spinal cord meninges, sheaths of peripheral nerves, and cutaneous receptors including Merkel cells (1990)
    Springer
    Anatomy and embryology 182 (1990), S. 529-537 
    Details
    ISSN: 1432-0568
    Keywords: Spinal cord meninges ; Nerve sheaths ; Cutaneous receptors ; Merkel cells ; Origin and development ; Avian embryo ; Herbst corpuscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The origin of cells covering the nervous system and the cutaneous receptors was studied using the quail-chick marking technique and light and electron microscopy. In the first experimental series the brachial neural tube of the quail was grafted in place of a corresponding neural tube segment of the chick embryo at HH-stages 10 to 14. In the second series the leg bud of quail embryos at HH-stages 18–20 was grafted in place of the leg bud of the chick embryos of the same stages and vice versa. It was found that all meningeal layers of the spinal cord, the perineurium and the endoneurium of peripheral nerves, as well as the capsular and inner space cells of Herbst sensory corpuscles, develop from the local mesenchymal cells. Schwann cells and cells of the inner core of sensory corpuscles are of neural crest origin. The precursors of Merkel cells migrate similarly to the Schwann cells into the limb bud where they later differentiate. This means that in addition to the Schwann cells and the melanocytes a further neural crest-derived subpopulation of cells enters the limb.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00186459
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  • 4
    Electronic Resource
    Electronic Resource
    A comparative physiological and morphological study of periodontal ligament mechanoreceptors represented in the trigeminal ganglion and the mesencephalic nucleus of the cat (1994)
    Springer
    Anatomy and embryology 190 (1994), S. 127-135 
    Details
    ISSN: 1432-0568
    Keywords: Periodontal ; Ligament ; Ruffini nerve ending ; Trigeminal ganglion ; Mesencephalic nucleus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A correlative morphological study was carried out on two electrophysiologically identified and located periodontal ligament mechanoreceptors in anaesthetised cats. One mechanoreceptor had its cell body in the mesencephalic nucleus and the other had its cell body in the trigeminal ganglion. Physiological recordings were made from each of their cell bodies. The two receptors were located by punctate and electrical stimuli in the labial aspect of the periodontal ligament of the left mandibular canine tooth. Both receptors had similar positions relative to the tooth apex and fulcrum and were situated in the labial part of the ligament in each tooth. The receptor loci were marked, and these regions were studied in a series of semi-thin and ultra-thin sections. Only Ruffini nerve endings were observed under each ink mark. Both Ruffini nerve endings branched, were unencapsulated and were incompletely surrounded by terminal Schwann cells with extensions projecting towards collagen bundles. The results indicate that periodontal ligament mechanoreceptors with cell bodies in the mesencephalic nucleus and those with their cell bodies in the trigeminal ganglion can both be Ruffini nerve endings. Furthermore, there was no apparent morphological difference between the two periodontal ligament mechanoreceptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00193410
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  • 5
    Electronic Resource
    Electronic Resource
    The Splotch mutation interferes with muscle development in the limbs (1993)
    Springer
    Anatomy and embryology 187 (1993), S. 153-160 
    Details
    ISSN: 1432-0568
    Keywords: Splotch mutation ; Pax-3 gene ; Skeletal muscle ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Homozygosity for the Splotch mutation causes neural tube and neural crest defects in mice. It has been demonstrated that Splotch mutant mice carry mutations in the homeodomain of the Pax-3 gene. Pax-3 is expressed in the neural tube, some neural crest derivatives, the mesenchyme of the limb bud and the somites. We have examined the development of the somite-derived skeletal muscles in homozygotes carrying the Splotch (Sp1H) mutation. Our results suggest that the Splotch mutation affects the development of skeletal muscles in a region-specific way: 1. The expression of the CMZ transgene in homozygotes reveals a disorganisation of the dermomyotome in whole stained embryos. 2. The axial musculature is reduced in size along a rostro-caudal gradient. 3. The muscle anlagen in the limbs develop much more slowly. Muscles of the head and the ventral body wall are normally developed in the mutant on day 13.5 of gestation. Recently, it has been shown that the myogenic precursors of the limbs are derived from the lateral half of the somite. The specific disturbance of muscle development in the limbs of Splotch mutants thus suggests a role for Pax-3 in the organisation of the somite, the production of trophic factors in the limb mesenchyme or an alteration of myogenic and mesenchymal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00171747
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  • 6
    Electronic Resource
    Electronic Resource
    A possible explanation for the response characteristics of multi-tooth periodontal ligament mechanoreceptors in the cat (1994)
    Springer
    Anatomy and embryology 190 (1994), S. 445-452 
    Details
    ISSN: 1432-0568
    Keywords: Innervation ; Periodontal ligament ; Mechanoreceptors ; Ruffini
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract During the course of a study on the morphology of periodontal ligament mechanoreceptors it was observed that a direct relation, without intervening bone, existed between the mandibular canine and first premolar tooth roots in the cat. An area, representing a window in the alveolar septal bone, extended 2–3 mm from the apex towards the tooth crown. Ruffini nerve terminals were observed amongst the collagen bundles in the ligament between the roots of the two teeth. Light and electron microscopy were used to identify the receptors. It is proposed that a periodontal ligament mechanoreceptor can respond to forces applied to adjacent teeth; movement of both teeth need not occur. This may explain the observation made in the past that single periodontal ligament mechanoreceptors respond to forces applied to more than one tooth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235491
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  • 7
    Electronic Resource
    Electronic Resource
    Sensory nerve endings in the hard palate and papilla incisiva of the rhesus monkey (1999)
    Springer
    Anatomy and embryology 199 (1999), S. 427-437 
    Details
    ISSN: 1432-0568
    Keywords: Key words Mechano-receptors ; Palate ; Merkel cell ; Ruffini corpuscle ; Free nerve ending ; Lamellated corpuscle ; Meissner corpuscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The sensory innervation of the hard palate of the rhesus monkey was studied by light and electron microscopy. The mucosa of the hard palate is subject to a particularly heavy mechanical load requiring functional specialisation of the horny epithelium in the form of thickenings – the papilla incisiva and eight pairs of rugae palatinae. A thin layer of firm connective tissue (lamina propria) attaches the mucosa to the periost of the hard palate. Sensory nerve fibres were found most abundantly in the papilla incisiva and first rugae palatinae. Their number decreases in an aboral direction. Five types of sensory nerve endings were found. Free nerve endings were ubiquitous in the epithelium and lamina propria. Merkel nerve endings were found in the basal layer of the epithelium of the papilla incisiva and rugae palatinae. Meissner corpuscles were located in the connective tissue between epithelial pegs, while lamellated corpuscles were seen below the epithelial pegs. Ruffini corpuscles were found in the deeper layer of the lamina propria. Thus, a variety of sensory nerve endings were found in the hard palate, especially in those areas that are in close contact with the tongue during chewing of food. This rich innervation suggests an important role in monitoring the mechanical properties of food and the position of the tongue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050241
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  • 8
    Electronic Resource
    Electronic Resource
    Tubulöse Formationen in Zisternen des Ergastoplasma in der Glia der Kleinhirnrinde beim Javaner-Affen (Macaca cynomolgus) (1973)
    Springer
    Acta neuropathologica 24 (1973), S. 340-344 
    Details
    ISSN: 1432-0533
    Keywords: Tubular Structures ; Glial Cells ; Cerebellar Cortex ; Macaca cynomolgus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the cerebellar cortex ofMacaca cynomolgus there are all types of glial cells as well as in other species. In the astrocytes, the Fañanas-cells and the microglia very often enlarged cisterns of the ergastoplasm occur in which tubular structures are located. These structures consist of very closely packed tubules with a diameter of 200 Å. The wall of the tubules is formed by a very fine granular material, their lumen is empty. These tubular structures of glial cells are only found in the cerebellar cortex. A possible similarity to viruses is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00685589
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  • 9
    Electronic Resource
    Electronic Resource
    Sensory nerve endings in the hard palate and papilla incisiva of the goat (1999)
    Springer
    Experimental brain research 129 (1999), S. 218-228 
    Details
    ISSN: 1432-1106
    Keywords: Key words Mechano-receptors ; Nociceptors ; Palate ; Merkel cell ; Ruffini corpuscle ; Free nerve ending ; Lamellated corpuscle ; Serotonin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The sensory innervation of the papilla incisiva in the hard palate of the domestic goat was studied with light and electron microscopy, supplemented by electrophysiological studies of free nerve endings. The goat lacks incisor teeth. Grass and leaves are not bitten, but pulled off by pressing them between the tongue and papilla incisiva. Thus, the masticatory mucosa is subject to particularly heavy mechanical loads requiring functional specialization of the horny epithelium in the form of thickening, i.e., the papilla incisiva and 12–14 pairs of rugae palatinae. A thin layer of firm connective tissue (lamina propria) attaches the mucosa to the periost of the hard palate. Sensory nerve fibers were found most abundantly in the papilla incisiva. Their number decreased drastically in aboral direction. A section through the first four rugae palatinae contains only about 10% of the number of free nerve endings found in the same area of mucosa from the papilla incisiva. Four types of sensory nerve endings were found. Free nerve endings were seen ubiquitously in the epithelium and superficial layer of the lamina propria. Merkel nerve endings were found in the bases of the epithelial thickenings in the papilla incisiva and rugae palatinae. Few Ruffini corpuscles were found in the deeper layer of the lamina propria, while lamellated corpuscles were seen just below the basement membrane of the epithelial pegs. Thus, a variety of sensory nerve endings were found in the hard palate, especially in those areas that are in close contact with the tongue during chewing of food. This rich innervation suggests an important role in monitoring the mechanical properties of food. Recordings were made from cell bodies supplying these terminals. Classic low-threshold, slowly adapting responses were observed in Aß afferent populations. This activity was probably mediated by Merkel type endings. Alternately, high-threshold and suprathreshold responses obtained from Aδ category afferents were likely to be nociceptive. In support of this, threshold and suprathreshold sensitization was observed following injection of serotonin into the receptive field of Aδ populations. This activity was likely to be derived from the aforementioned free nerve endings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050892
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  • 10
    Electronic Resource
    Electronic Resource
    Lectin and proteoglycan histochemistry of Merkel cell carcinomas (2001)
    Copenhagen : Munksgaard International Publishers
    Experimental dermatology 10 (2001), S. 0 
    Details
    ISSN: 1600-0625
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Changes in carbohydrate residue expression and in proteoglycan distribution occur during different stages of tumor development and progression. However, few data concerning carbohydrate residue analysis as performed by lectin histochemistry and proteoglycan distribution of Merkel cell carcinoma, a rare malignant tumor of the skin, have been reported. Hence, lectin- and proteoglycan immunohistochemistry was performed on paraffin wax material of 9 cases of Merkel cell carcinomas characterized by cytokeratin and neurofilament immunohistochemistry. The lectin binding pattern of tumor cells varied between lectins with different sugar binding specificities, while within a given nominal sugar specificity intensities were remarkably similar between tumors from different patients. The most intensive reaction was observed using Con A (mannose/glucose-specific) followed by LCA with the same specificity and the N-Acetyl glucosamine-specific lectins (WGA, UDA, CMA), while no fucose binding sites were detected (UEA-I). In addition, N-Acetyl galactosamine residues were only occasionally detected. The lectin binding pattern of Merkel cell carcinoma cells indicated that predominantly N-linked glycans and not O-linked glycans, typical for mucins of most epithelia, were present. Hence these tumor cells were relatively undifferentiated and resembled stem cells more closely than differentiated epithelia. The tumor stroma was especially evaluated in this study and showed a lectin reaction, which was intermediate between the tumor cells and extra-tumoral stroma. For example, the reactions of N-Acetyl galactosamine-specific lectins were intensive in the extra-tumoral stroma but nearly negative in tumor cells, while the lectin reaction of the intra-tumoral stroma was similar to the cellular reaction. These results indicated an influence of tumor cells on the stromal constituents. Antibodies against chondroitin type glycosaminoglycans reacted with the tumor stroma and the pericellular substance around the tumor cells most intensely in – and around the major tumor septae which, in general, were well vascularized. The most intensive immunoreactivity was detected using the chondroitin-6-sulfate antibody. The cellular and membrane-associated reaction for heparan sulfate was less intensive in comparison to epidermal cells. In conclusion the pattern of lectin-binding sites, the high chondroitin(sulfate) specific reactivity and the relatively low intensity of heparan sulfate immunohistochemistry indicate a low degree of differentiation and high malignity of the tumors, which is consistent with the clinical behavior of Merkel cell carcinomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1034/j.1600-0625.2001.010002100.x
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