Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Distribution of glial fibrillary acidic protein-immunopositive structures in the brain of the red-eared freshwater turtle (Pseudemys scripta elegans) (1994)
    Springer
    Anatomy and embryology 189 (1994), S. 421-434 
    Details
    ISSN: 1432-0568
    Keywords: Glial fibrillary acidic protein ; Glia ; Turtle brain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The distribution of glial fibrillary acidic protein (GFAP)-immunoreactivity is described in serial Vibratome sections of the turtle brain. The results are discussed in relation to our previous studies of rat and chicken brains. In the turtle brain, the distribution of GFAP-positive elements is rather evenly abundant as compared to that observed in the chicken and rat. The GFAP-positive structures are fibers of different length and orientation, but the stellate cells are not GFAP-positive. The basic systems is the radial ependymoglia, directed from the ventricles toward the outer surface of the brain. This system also contains some transverse and randomly oriented fibers. The cell bodies are not usually GFAP-positive. The large brain tracts could be recognized by their weak immunostaining, but gray matter nuclei could not be identified on the basis of immunostaining against GFAP. The layers of the optic tectum could be distinguished, as well as the gray and white matter of brain stem and spinal cord and the molecular and granular layers of the cerebellum. In the cerebellum, a fiber system resembling the Bergmann-fibers, a strong midline raphe and coarse transverse fibers could be observed. These latter fibers have no equivalent in other cerebella. Their perikarya proved also to be GFAP-positive, and seemed to be dividing in the adult turtle brain. We conclude that the appearance of GFAP-positive stellate cells had a great importance in the evolution of avian and mammalian brains strengthening the thicker brain walls and assisting in the formation of local differences of GFAP-immunoreactivity in different brain areas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185437
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Distribution of glial fibrillary acidic protein-immunopositive structures in the developing brain of the turtle Mauremys leprosa (1997)
    Springer
    Anatomy and embryology 196 (1997), S. 47-65 
    Details
    ISSN: 1432-0568
    Keywords: Key words Development of turtle brain ; Turtle glia ; Development of glia ; GFAP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  This study is a continuation of the description of the glial fibrillary acidic protein (GFAP)-immunopositive structures in the adult turtle brain (Kálmán et al. 1994) and presents a comprehensive description of the development of these structures from the 20th embryonic day (E20) to the adult age. GFAP-immunopositive elements were first detected at E28 and by E34 the GFAP-immunopositivity was apparent throughout the brain, except the cerebellum. The appearance of GFAP seemed to be related to the end of cell migration and the formation of the thickened parts of the brain wall, such as the dorsal ventricular ridge. After hatching the pattern of the GFAP-immunopositivity differed from that in the adult only in minute details, except for the brain tracts in which GFAP-pattern was still changing due to myelination, and the molecular layer of the cerebellum in which a transverse fiber system appeared. The GFAP-positive elements belonged originally to the ependymoglia, but later the distortion due to the morphogenetic processes of branching and division changed the pattern almost beyond recognition. In some cases cell bodies – ependymal and non-ependymal – appeared to be GFAP-positive, but no astrocytes (i.e., stellate cells) were detected. The results are discussed in the light of previous observations on developing mammalian, avian and lizard brains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004290050079
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Specific patterns of neuron arrangement and of synaptic articulation in the medial geniculate body (1976)
    Springer
    Experimental brain research 26 (1976), S. 1-17 
    Details
    ISSN: 1432-1106
    Keywords: Medial geniculate body ; Neuronal geometry ; Synaptic triplets ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Golgi and electron microscopic analysis of the known cellular layers in concentric shells of the ventro-lateral portion of the medial geniculate body revealed a flat grid of high density neuropil filling the space between the geniculocortical relay cells, forming essentially a single cell layer in each lamina. The “skeleton” of this neuropil grid is made up by the interdigitating dendritic tufts of the geniculocortical relay cells, joined together by a rich system of desmosomoid adhesion plaques. The “holes” of the “skeleton” are filled in by the multilobed dendritic appendages of Golgi type II interneurons and the grape-like terminals of the inferior collicular specific afferents. Additional axon terminals of other sources — terminals of descending corticogenicular fibers, axons of the Golgi type II interneurons and terminals of the initial collaterals of the geniculocortical relay cells — contribute only to a very insignificant fraction of neuropil volume. The Golgi type II interneurons are oriented in perpendicular direction to the cell layers so that they may bridge with their dendrites several successive layers. Although the general expression “synaptic glomeruli” used in other relay nuclei for this type of specific synaptic arrangement is hardly applicable to this grid-like neuropil, the essential synaptic articulation pattern of all thalamic relay nuclei is well maintained. The specific inferior collicular afferents are presynaptic to both relay cell dendrites and to the multilobed dendritic appendages of Golgi type II cells, which in turn are presynaptic to the same dendritic regions of the relay cells receiving the bulk of the specific afferents.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235246
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Types of interneurons and their participation in the neuronal network of the medial geniculate body (1976)
    Springer
    Experimental brain research 26 (1976), S. 19-37 
    Details
    ISSN: 1432-1106
    Keywords: Medial geniculate body ; Interneurons ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three different types of interneurons can be separated in the Golgi picture, and many of their details can be identified under the electron microscope, in the medial geniculate body (MGB) of the cat: (1) typical short axon Golgi II. cells of the thalamic type, (2) somewhat larger Golgi type II cells with medium range axon, and (3) spidery neurogliform short axon cells. The most distinctive features of the two first types (1) and (2) are their irregular drumstick shape appendages, increasing in number as well as in length and irregularity of their stalks towards the periphery of the dendrites. These appendages form the vast majority of synaptic profiles in the aggregations of synaptic neuropil (glomeruli) of the nuclei, and they are both presynaptic and postsynaptic by the usual standards applied for the evaluation of the polarity of synapses. The characteristic beaded dendrites of the (3) neurogliform cell type can be recognised particularly easily in the electron microscope picture. They are both presynaptic and postsynaptic in structural polarity. All identified process profiles of interneurons contain flattened (F.-type) or pleomorphic synaptic vesicles. Membrane contacts, in which the interneurons appear to be presynaptic are either of the symmetric (Gray type II) or of an intermediate type. The membrane contacts of postsynaptic portions of the interneurons are usually of the asymmetric type (Gray type I) and the presynaptic profiles contain round (R-type) vesicles. The larger one have been shown already earlier to be derived from specific sensory (inferior collicular) afferents, while many of the smaller ones could be identified in the present study as being derived from cortico-geniculate descending pathways, arising from the auditory areas. Some of the synaptic contacts of the interneurons are apparently derived from other interneurons, the presynaptic profiles being often equivocal or more likely of axonal origin (all interneurons have clear axons in the Golgi picture). The occurrence of three distinct types of interneurons — probably all of inhibitory nature — the complexity in synaptic arrangement, and more particularly in the dendritic linkage of numerous synaptic sites does not favour such simple explanations as surround inhibition by forward or by backward inhibition, but suggests more sophisticated modes of impulse processing in the MGB.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235247
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Neuron morphology and synaptic architecture in the medial superior olivary nucleus (1983)
    Springer
    Experimental brain research 52 (1983), S. 315-327 
    Details
    ISSN: 1432-1106
    Keywords: Medial superior olive ; Neuronal morphology ; Golgi, electron microscope and horseradish peroxidase techniques
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Dendritic arborization pattern, spatial and synaptic relations of various neuron types and the terminal distribution of afferent axons of various origin were studied in the medial superior olivary nucleus of the cat using Golgi, degeneration, electron microscope and horseradish peroxidase techniques. Three types of neurons clearly different in morphological features, distribution, neighbourhood relations, input and output characteristics were distinguished: (1) fusiform cells having specific dendritic orientations and arborization patterns and synaptic relations to various types of terminal axon arborizations (2) multipolar neurons with wavy dendrites bearing spine-like appendages, receiving relatively few synaptic contacts and having a locally arborizing axon, and (3) elongated marginal cells, largely restricted to the fibrous capsule of the nucleus. The fusiform and marginal neurons were identified by retrograde peroxidase labeling as the olivo-collicular projection cells. Ultrastructural analysis of normal and experimental material revealed the presence of four distinct kinds of axon terminals differing in size, synaptic vesicles type, relation to postsynaptic targets and in origin: (i) large terminals with multiple extended asymmetric synaptic membrane specializations and containing round, clear vesicles arise from the spherical cells of the ipsilateral anteroventral cochlear nucleus, (ii) most of the small axon terminal profiles — engaged in asymmetric synaptic contacts — originated from the trapezoid nucleus, (iii) terminal boutons containing pleomorphic vesicles belong to fibers descending from the ipsilateral multipolar neurons in the central nucleus of the inferior colliculus and from the nuclei of the lateral lemniscus while (iv) boutons containing exclusively ovoid vesicles and remaining intact after complete deafferentation of the nucleus were considered to be of local origin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Synaptic architecture in the medial geniculate body (ventral division) (1968)
    Springer
    Experimental brain research 6 (1968), S. 306-323 
    Details
    ISSN: 1432-1106
    Keywords: Medial geniculate body (ventral division) ; Synaptic clusters ; Auditory afferents ; Golgi type II neurons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron and light microscope study of the ventral division of the medial geniculate body using Golgi techniques, neurofibrillar stains and experimentally induced secondary degeneration. Geniculo-cortical relay cells and Golgi type II interneurons are easily recognized in the Golgi picture; under the electron microscope the two cell types and their dendrites can be identified on the basis of their different plasma structure. Synaptic arrangement of this region is analysed by a detailed comparison between the EM structure and the Golgi picture of the dendrites and axonal arborizations, the neurofibrillar picture of synapses, as well as degeneration pictures after lesions of the inferior colliculus and of the auditory cortical fields. Criteria derived from the light microscope study concerning size and distribution of various nerve endings, as well as secondary degeneration, have been used to identify various axon endings under the EM. The synapses of specific auditory afferents are confined to synaptic clusters arranged around the interdigitating dendritic tufts of relay cells. Although these synaptic clusters resemble in many respects the synaptic glomeruli of the lateral geniculate body, they cannot be termed as such due to lack of a glial capsule and also to less regularity in topographic arrangement of their various axonal and dendritic elements. It became nevertheless possible to identify in the synaptic clusters (1) the terminals of the specific auditory afferents of inferior collicular origin, (2) the axon terminals of Golgi II type neurons and, with less certainty (3) another axonal ending that might belong to descending cortical fibers originating from the auditory region. All types of axons have contacts with the dendrites of relay cells. It is not quite clear, whether the dendrites of Golgi type II cells are involved in these synaptic clusters, but this is very probable. Axo-axonic synapses between type (1) and (2) are frequent, type (1) (the auditory afferent) being always presynaptic. Very numerous synaptic contacts on the distal dendrites of both main cell types are found outside the synaptic clusters. They do not belong to either type (1) or type (2), many look like type (3) and may undergo degeneration after lesions of auditory cortical regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233182
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...