An ultrastructural study of the neurosecretory cells of the medial vascular prechiasmatic gland
| Autor: | Yvi J. Le Beux |
|---|---|
| Rok vydání: | 1972 |
| Předmět: |
Histology
Ependymal Cell Unmyelinated nerve fiber Biology Cytoplasmic Granules Microfilament Synaptic vesicle Pathology and Forensic Medicine Ependyma Neuropil medicine Animals Axon Nerve Endings Neurons Vesicle Cell Biology Anatomy Neurosecretory Systems Axons Rats Microscopy Electron medicine.anatomical_structure Synapses Collagen Synaptic Vesicles Lysosomes Neuroglia Ribosomes Free nerve ending Glycogen |
| Zdroj: | Zeitschrift f�r Zellforschung und Mikroskopische Anatomie. 127:439-461 |
| ISSN: | 1432-0878 0302-766X |
| DOI: | 10.1007/bf00306865 |
| Popis: | On the basis of the present electron microscopic study of the rat median vascular prechiasmatic gland, the unmyelinated nerve fibers containing dense-cored vesicles may be classified in three categories. (1) Nerve endings containing isomorphic rounded dense-cored vesicles, 800–1600 A in diameter with a predominance of vesicles between 1100 and 1300 A. These vesicles are synthesized in the nerve cell perikarya which are localized principally in the lamina profunda of the outer subpial layer and also in the neuropil of the inner glial covering layer. One or more “cholinergic” axon terminals are in contact with the surface of these nerve cell perikarya. The dense-cored vesicles travel in the axonal process which branches into an extensive terminal network characterized by the presence of small varicosities. They abut on the pericapillary spaces but never against another neuron or effector cell. A few nerve processes course between the ependymal cells and terminate in the preoptic recess of the third ventricle. The dense-cored vesicles may contain one of the primary monoamines. (2) Nerve endings containing pleomorphic dense-cored vesicles, 500–1600 A in diameter with a predominance of vesicles between 800 and 1100 A. The latter granular vesicles are associated with small, clear-centered vesicles, 260–550 A in diameter, which are often aggregated in the vicinity of thickenings of the plasma membrane and of cytoplasmic dense projections. The intercellular space and the cell plasma membrane, however, do not display any modification facing these structures. Synapse-like contacts are observed between these nerve endings and cells containing a great amount of microfilaments and glycogen particles in their cytoplasm. The latter cells possibly represent processes of ependymal cells. (3) Nerve endings containing a few large dense-cored vesicles in addition to a majority of synaptic vesicles. |
| Databáze: | OpenAIRE |
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