[Effect of noise-induced stress on the quantitative characteristics of rat brain synapses].

Rats were exposed to white noise for 1, 2 and 3 weeks. Electron microscopy was used to examine brain sections. The number of synaptic junctions was calculated in the auditory and motor areas of the brain cortex.

[Neurono-glial changes in the cerebral cortex of animals exposed to white noise].

The rat acoustic cortex has been studied at light optic and ultrastructural levels under the white noise stimulation. After the noise stimulation for 7 days, micropunctate hemorrhages, proliferation and hypertrophy in cells of microglia and astrocytic glia are noted. After the noise stimulation for 21 days, the neuroglial reaction becomes less pronounced, there are no hemorrhages, a great amount of neurons with peripheral and total chromatolysis appear.

[Effect of white noise on the rat auditory cortex ultrastructure].

Changes in ultrastructure of neurones and glial cells of rat auditory cortex were studied after exposure to white noise for 21 days. Appearance of light neurones with peripheral chromatolysis and the increased number of lysosomes, pigment granules and vacuoles were recorded both in the neurones and glial cells. It is concluded that exposure to white noise in chronic experiments is the pathogenic factor which causes destruction in the neurons and glial cells of the auditory cortex.

[Structural and ultrastructural changes induced by angiotensin II in the cerebral cortex of animals].

Structure of capillaries, pericapillary glia and neurons of the sensomotor cerebral cortex was studied in rats after intraperitoneal injections of angiotensin-II (0.05 mg/kg of the body weight) administered once for 1, 3, 7, 14 and 21 days. The animals were decapitated 5 and 15 min after a single injection, and at repeated injections--15 min after the last one.

[Gliovascular changes in the rat central nervous system induced by angiotensin II].

The action of the synthetic polypeptide hormone angiotensin-II (A-II) on the ultrastructure of capillaries and perivascular glia of the cerebral cortex was studied in experiments on adult male rats. Intraperitoneal injections of the hormone are accompanied by swelling of the growing fibers and bodies of the precapillary glia (astrocytes), and by a strong narrowing of the capillary lumen. The endothelium of these vessels swells and layer inclusions appear in the cytoplasm of endothelial cells.