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W Ovtscharoff

Publications and source records attributed to W Ovtscharoff.

10 recordsLinked to original sources
PubMed1979

Synaptic organization of the medial acessory olivary nucleus of the cat.

Light microscopically the morphological characteristic of neurons and ultrastructurally the synaptic organization of medial accessory olivary nucleus of cat was studied. Different types of chemically mediated as well as electric synapses were observed. The terminal boutons contain mainly clear synaptic vesicles, but small and large dense core vesicles are also available. In the neuropil of the nucleus characteristic glomeruli with central dendritic core were establish. The dendritic profiles were connected with numerous gap junctions and attachment plaques. The apposition without any synaptic specializations in a large area of the cell membrane of adjacent neurons was also observed. In some cases oval structures with size 450--650 A which we called submembraneous dense bodies were established under one of the apposite membranes.

Accessory Nerve↗
PubMed1978

Visualization of proteinaceous granules in the clear synaptic vesicles.

A method for demonstration of electron-dense particles within clear synaptic vesicles from various areas of the CNS as well as from neuromuscular junctions of rat is described. Electron-dense granules of 70-250 A were visible in the center of the synaptic vesicles, or in some cases excentrically situated and bound to the vesicular membrane. Digestion with proteolytic enzymes lead to a negative reaction, whereas treatment with hyaluronidase and neuraminidase, as well as the lipid extraction had no effect. Based on the obtained data, it may be assumed that this method manifests the proteinaceous structures.

Animals↗
PubMed1978

Ultrastructural changes in the anterior horn synapses of rat spinal cord under different locomotor conditions.

Ultrastructural changes in axodendritic synapses of the spinal cord ventral horn are studied in rats subjected to different locomotor conditions: immobilization, control and physical loading. Enhanced motor activity results in a reduction of the number of synaptic vesicles in the axon terminal, as well as flattening and diminution of their size. Other changes correlated with the different motor regimes are likewise established in the number of terminal ending's mitochondria, in "active zones", in subjunctional dense bodies, and in the bouton area. Data are treated by means of variation analysis. The significance of differences is established by "T"-criterion.

Animals↗
PubMed1977

Cytochemical localization of adenosine triphosphatase and thiamine pyrophosphatase in the synapases of rat's cerebral cortex.

Ultrastructural distribution of adenosine triphosphatase and thiamine pyrophosphatase in synapses of rat's cerebral cortex was studied. Adenosine triphosphatase activity in some synaptic vesicles and mitochondria, on pre- and postsynaptic membranes, as well as in the postsynaptic thickening was established. The reaction specificity was proved by means of some controls: various concentrations of ouabain, NaF, NiCl2, cysteine, substrate free medium and non-specific substrates - cocarboxylase and beta-glycerophosphate. At the thiamine pyrophatase reaction, the enzyme positive product was found on the membrane of some clear synaptic vesicles, on the singl sacs of smooth endoplasmic reticulum in the axon terminal, and bouton cell membrane. Substrate free medium, addition of cystein and substitution of orininal substrate with adenosine triphosphate and beta-glycerophosphate as controls were used. The fine structure localization of both enzymes in synaptic structures suggests their important role in the synaptic function.

Adenosine Triphosphatases↗
PubMed1977

Ultrastructural localization of choline acetyltransferase in the CNS of rat.

The ultrastructural localization of choline acetyltransferase in various regions of rat's CNS is studied. It is established that the reaction product is located in some structures of the neuronal perikarya--on the outer surface of the rough endoplasmic reticulum sacs, along the vesicular profiles and in the mitochondria. Electron dense material is found in the axon terminal as well as, where enzyme activity is detected in the cytoplasm, on the membrane of spherical and flat synaptic vesicles and in the mitochondria. These findings, the control results and literature data are discussed.

Animals↗
PubMed1976

Ultrastructural changes in satellite cells after denervation and reinnervation of skeletal muscles.

Changes taking place in the satellite cells after denervation and reinnervation of skeletal muscles are studied. A certain degree of similarity and synchrony of the changes occurring in these cells and in the muscle fibers is established during the degenerative and regenerative processes. Formation of new satellite cells and fusion of the same with muscle cells is not observed. These findings are explained by the fact that postdenervation changes in the skeletal muscles are not so heavy as in their direct lesion when, according to literature data, the satellite cells participate directly in the reparative process.

Animals↗
PubMed1975

A method for demonstration of synaptic densities in CNS.

The synaptic densities in rat CNS were demonstrated using an alcohol solution of uranyl acetate at pH 5.0-6.0 of unosmicated material. A number of procedures were performed to establish the chemical characteristics of the structures stained by the method described.

Animals↗
PubMed1975

Cytochemistry and morphology of synaptic structures in the cerebral cortex of rat.

Studies have been carried out on the synapses in the cerebral cortex of rat by using impregnation with ethanolic solution of phosphotungstic acid, contrast staining with ruthenium red and impregnation with bismuth iodide, with or without subsequent uranyl acetate and lead citrate staining. It has been established that dense projections are adequately visualized with methods demonstrating basic chemical groups (phosphotungstic acid and bismuth iodide), whereas the synaptic vesicles are stained by techniques demonstrating acid chemical groups (ruthenium red and uranyl acetate and lead citrate). On the basis of these observations a hypothesis is forwarded concerning the mechanisms of migration of synaptic vesicles towards the presynaptic membrane. Measurements of the parameters of the dense projections suggest that the configuration of the presynaptic vesicular grid is not uniform along the presynaptic areas.

Acetates↗
PubMed1975

Distribution of ruthenium red staining material in the cerebral cortex of rat.

The ultrastructural distribution of ruthenium red staining material is studied in the cerebral cortex of rat. It is established that the material is located equally along the cell surface of the neurons, glial and endothelial cells, and within a number of cell organelles: mitochondria, smooth endoplasmic reticulum, synaptic vesicles and throughout both membranes of the nuclear envelope. Using digestion with hyaluronidase and trypsin, and lipid extraction an attempt is made to determine the participation of some chemical compounds such as acid mucopolysaccharides, glycoproteins, glycolipids and acid polypeptides in the composition of the ruthenium red-positive material. Moreover, the problem of the optimal conditions for the carrying out of ruthenium red staining in the CNS is discussed.

Animals↗