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
    An electron microscopic study of the mediodorsal cerebral cortex in the lizard Agama agama (1981)
    Springer
    Anatomy and embryology 163 (1981), S. 185-200 
    Details
    ISSN: 1432-0568
    Keywords: Cerebral cortex ; Neurons ; Lizard ; Tanycytes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An electron microscopic analysis was made of the small-celled part of the mediodorsal cortex of the lizard Agama agama. This cortex consists of four layers: Superficial plexiform layer, cellular layer, deep plexiform layer and fiber layer. In the superficial plexiform layer one type of solitary neuron with smooth dendrites is present. Three types of axon terminals can be observed: terminals with a moderately electron dense matrix packed with spherical vesicles (S1 type), axon terminals with an electron lucent matrix containing fewer spherical synaptic vesicles than the S1 type (S2 type) and axon terminals with an electron lucent matrix and scattered pleomorphic synaptic vesicles (F type). F type axon terminals are larger than S terminals. At the pial surface endfeet of tanycytic processes form a limiting glial layer, contacting one another by means of gap junctions. In the cellular layer perikarya of pyramidal neurons are densely packed. The karyoplasm of these neurons shows either evenly dispersed or discretely clumped chromatin. Spiny dendrites arise from the perikarya and extend into both the superficial and deep plexiform layers. The structure of the deep plexiform layer is roughly similar to that of the superficial plexiform layer. The fiber layer contains the majority of the afferent and efferent axons of the mediodorsal cortex. The axons are myelinated and unmyelinated. Between the fibers, scattered solitary neurons are present, often accompanied by glial cells. The lateral ventricle beneath the fiber layer is lined by a single row of ependymal tanycytes. Tanycytic processes traverse the cortical layers and may form endfeet at the pial surface. Protoplasmic excresenses from some ependymal cells protrude into the ventricle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00320675
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Anterograde neuroanatomical tracing with Phaseolus vulgaris-leucoagglutinin combined with immunocytochemistry of gamma-amino butyric acid, choline acetyltransferase or serotonin (1988)
    Springer
    Histochemistry and cell biology 89 (1988), S. 421-428 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to associate specific fiber projections in the central nervous system with specific target neurons, procedures were developed in which the anterograde neuroanatomical tracing technique utilizing Phaseolus vulgaris-leucoagglutinin (PHA-L) is combined with immunocytochemistry of three (different) neuronal markers: gammaamino butyric acid, choline acetyltransferase, and serotonin. A double, indirect, peroxidase-antiperoxidase staining method is used on free-floating brain sections. The primary antiserum against the PHA-L (first primary antiserum) is mixed with the primary antiserum against the neuronal marker (second primary antiserum). These primary antisera are raised in different animal species. Following the incubation in the cocktail of primary antisera, the sections are incubated in a cocktail of two secondary antisera. The transported PHA-L is then visualized by incubation in a peroxidase-antiperoxidase complex and subsequent reaction with nickel-enhanced diaminobenzidine/H2O2 (blue reaction product in PHA-L-labeled neurons and fibers). Incubation is continued with peroxidase-antiperoxidase antibodies raised in the animal species in which the second primary antiserum is developed, and the staining is completed by treatment with diaminobenzidine/H2O2 (brown reaction product in the target neurons). The present results suggest that PHA-L-tracing can be combined with immunocytochemistry of a variety of target neuron-related antigens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00492597
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Immunocytochemical applications in neuroanatomy (1988)
    Springer
    Histochemistry and cell biology 90 (1988), S. 85-97 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the present paper we review immunocytochemical methods for anterograde tracing with the lectin Phaseolus vulgaris-leucoagglutinin (PHA-L), combined PHA-L tracing — neurotransmitter immunocytochemistry, and the immunocytochemical localization of receptor proteins. These methods will be mainly illustrated by examples from tracing- and neurotransmitter studies on the cholinergic basal forebrain system. The morphology of PHA-L labeled neurons strongly resembles that of Golgi impregnated neurons. The complete axonal trajectories and patterns of presynaptic endings of PHA-L labeled neurons are visualized, both for light- and electron microscopic application. PHA-L-tracing can very well be combined with second immunocytochemical labeling procedures. In this way, traced pathways can be studied in their relation to chemically identified fiber systems or target neurons. Application of immunocytochemistry for the localization of the muscarinic acetylcholine receptor, albeit in its early stages, holds great promise for the near future.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500973
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ultrastructure of giant and small thalamic terminals of cortical origin: a study of the projections from the barrel cortex in mice using Phaseolus vulgaris leuco-agglutinin (PHA-L) (1991)
    Springer
    Experimental brain research 87 (1991), S. 159-172 
    Details
    ISSN: 1432-1106
    Keywords: Corticothalamic projection ; Somatosensory system ; Barrel ; Phaseolus vulgaris ; leucoagglutinin ; Electron microscopy ; Mouse ; Synaptic glomerulus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary By means of tracing with the lectin Phaseolusvulgaris leucoagglutinin (PHA-L), we examined in the thalamus of the mouse, the axon terminals of fibers originating in the barrel cortex. Vibratome sections of the brain were subjected to PHA-L immunocytochemistry and processed for light and electron microscopy. We observed small (0.5–0.8 μm in diameter) varicosities of labeled fibers in the nucleus ventrobasalis (VB) and the nucleus posterior (PO) as well as labeled giant terminals (3–5 μm in diameter) in PO. The analysis involved examination of serial sections and computer-aided reconstruction of several terminals. The small varicosities in VB appear to be small axon terminals forming distinct asymmetric synapses with small dendritic profiles. Some labeled terminals are apposed to, but not synaptically related with, the cell bodies of neurons in VB that are retrogradely labeled with PHA-L. The small varicosities seen with the light microscope in PO are terminals forming asymmetric synapses with dendritic shafts. The giant terminals in PO appear as large, vesicle-filled profiles forming part of synaptic glomeruli, i.e. complexes of one corticothalamic terminal engulfing several excrescences of a single dendrite. A giant terminal forms several asymmetric synapses (about 8) with these excrescences, as well as numerous (up to 15) puncta adhaerentia. The glomeruli are enveloped in glial lamellae, and they are often found at the bifurcations of primary dendritic segments. We suggest that the small terminals in VB are in the service of feedback signalling from the barrel cortex to its principal thalamic relay nucleus; the functional importance of this projection may reside in increased spatio-temporal discrimination. We interpret the giant terminals in PO as elements serving feed-forward processing, allowing the barrel cortex to influence, via PO, parts of the motor pathway modulating the animal's ongoing behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228517
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Stellate neurons in rat dorsal cochlear nucleus studied with combined Golgi impregnation and electron microscopy: synaptic connections and mutual coupling by gap junctions (1984)
    Springer
    Journal of neurocytology 13 (1984), S. 639-664 
    Details
    ISSN: 1573-7381
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Stellate neurons in the outer two layers of the rat dorsal cochlear nucleus (DCN) were studied by the Golgi-EM method. Stellate cell bodies are usually spherical or ovoidal and range from 9 μm to 14 μm in mean diameter. The smallest cells are situated underneath the ependymal layer and the largest cells in layer 2. Primary dendrites are short, thin and smooth and arise abruptly from the perikaryon, without a tapering main stem. Meandering secondary and tertiary dendrites extend in all directions, carry few pleomorphic spines lacking a spine apparatus and often show artifactual beading. The axons are impregnated only for a short distance (10–45 μm). The nucleus is indented, the nucleolus varies in position, and the chromatin, evenly dispersed in the centre, forms small clumps along the nuclear envelope. The cytoplasm is rich in free polyribosomes and contains scattered cisterns of granular endoplasmic reticulum. Varicosities of thin fibres, containing round synaptic vesicles, form asymmetric synapses on perikarya, dendritic shafts and spines of stellate cells. Such fibres run parallel to the long axis of the DCN or are oriented radially and are interpreted as axons of cochlear granule cells. Two kinds of bouton containing pleomorphic vesicles, one kind electron lucent and the other electron dense, form symmetric synapses on perikarya and dendritic shafts of stellate cells. The lucent boutons occur more frequently than the dense boutons, especially on the distal dendritic branches. The boutons with pleomorphic vesicles presumably represent terminals of local circuit neurons, probably the stellate and cartwheel cells. In addition, stellate cells show numerous dendro-somatic and dendro-dendritic appositions characterized by gap junctions and puncta adhaerentia. Most of the dendrites involved in these appositions resemble stellate cell dendrites and it is concluded that DCN stellate cells are coupled electrotonically with one another. The axons of stellate cells acquire a thin myelin sheath. Since the Golgi impregnation did not stain axons of stellate cells past this point, we were unable to demonstrate the synaptic targets of stellate cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01148083
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Efferent projections from the lateral septal nucleus to the anterior hypothalamus in the rat: A study combining Phaseolus vulgaris-leucoagglutinin tracing with vasopressin immunocytochemistry (1990)
    Springer
    Cell & tissue research 261 (1990), S. 17-23 
    Details
    ISSN: 1432-0878
    Keywords: Lateral septal nucleus ; Efferent projections ; Tracer studies ; Phaseolus vulgaris-leucoagglutinin ; Vasopressin immunocytochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tracer Phaseolus vulgaris-leucoagglutinin (PHA-L) was injected into the lateral septum of the rat at different rostrocaudal locations to study the efferent septal projections to the anterior hypothalamus. For spatial correlation of these septofugal elements with the vasopressinergic system a dual immunocytochemical technique was used (i) to demonstrate nerve fibers and their corresponding bouton-like structures labeled with the tracer, and (ii) to identify vasopressin in the same section. The hypothalamic paraventricular and supraoptic nuclei, the accessory hypothalamic magnocellular system, and the suprachiasmatic nucleus are recipients of PHA-L-labeled fibers from all parts of the lateral septum. Close appositions between (i) these axons and their varicosities, and (ii) vasopressin-immunoreactive perikarya and their processes, putatively indicating functional interrelationships, were observed in all these nuclear areas, especially in their neuropil formations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00329434
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Terminal degeneration in the mediodorsal cerebral cortex of the lizard Agama agama: Light and electron microscopy (1982)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 172 (1982), S. 45-58 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The degeneration of axon terminals in the small-celled part of the mediodorsal cortex (sMDC) of the lizard Agama agama has been studied after lesions in the dorsal cortex at various survival periods. The Fink-Heimer stain was used to map and demonstrate terminal degeneration with the light and electron microscope. Electron microscopy was used to identify and describe degenerating boutons ultrastructurally. One sham-operated and three unoperated animals served as controls. Between 6 and 21 days postsurgically, degenerating terminals can be seen through 80% of the superficial plexiform layer, the zone adjacent to the cellular layer remaining free of degeneration. Swelling of dendrites in the outer part of the superficial plexiform layer and increased numbers of vacuolar invaginations, both present at short (24 hr-6 days; peak at 48-54 hr) survival periods, can be regarded as reaction to the surgical trauma. Degeneration of axon terminals takes three forms, all of the electron-dense type: gray boutons, degenerating bouton-dendritic spine complexes surrounded or engulfed by glia, and degeneration debris inside glial processes. Several forms of terminal degeneration occur concomitantly at any short (3-12 days) survival time. At longer survival times (15-21 days) only debris is present. From 6 days on, considerable numbers of degenerating structures are present, but the majority of degenerating boutons and debris are associated with reactive glia rather than with dendrites. From these observations it is concluded that in this lizard application of the combined degeneration-Golgi-EM technique would probably lead to little success. Electron microscopy of Fink-Heimer-stained sections suggests that degenerating bouton-dendritic spine complexes and degeneration debris accumulate silver particles, whereas gray boutons do not.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051720105
    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...