[Substance P as a factor in resistance to emotional stress].

The effect of substance P--an endogenous brain peptide--on the resistance to chronic emotional stress was studied in rats. A single administration of the peptide (125 or 250 mkg/kg) elicits a highly significant increase of rats resistance to chronic emotional stress and reduces the raise of adrenals weight, hemodynamic fluctuations and emotional reactivity.

[Effect of substance P on behavior in the rabbit and the activity of cortical neurons during training].

Subcutaneous injection of substance P to rabbits in a dose of 250 mcg/kg elicited a transitory disappearance of motor reactions to painful reinforcing stimuli and a reduction of their probability to reinforced and inhibitory light flashes, as well as a protracted heart rate increase and decrease of respiration rate. One third of the neurones recorded decreased their background firing level and or excitatory components of the reactions to reinforcement and conditioned light flashes. The decrease was most distinctly seen in the sensorimotor cortex and less pronounced in the visual cortical area and hippocampus.

[Peptide therapy of sleep disorders in neurotic rats].

As a result of chronic stress, anxiety appeared in the rats behaviour, motor activity increased, heart rate quickened, blood pressure raised, conditioned instrumental alimentary reflexes missed, the duration of deep phases of sleep lowered, time of falling asleep became longer, the number of awakening increased. The change in quantitative characteristics of sleep was accompanied by its worsening, especially of rapid sleep. Administration of substance P (SP) eledoisin hexopeptide (EH) (250 mcg/kg), 100-200 mcg/kg of delta sleep peptide and 10 mcg/kg of ethylcrotyl barbiturate improved the rats behaviour and sleep parameters.

[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.

[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.