[Function of the hypothalamo-thyroid system after administration of kainate into the ventrolateral portion of the medulla oblongata].

Contribution of the bulbar structures to mechanisms of realization of the hypothalamo-thyroid system feedback was studied in experiments on 73 adult male Wistar rats. Histologically confirmed unilateral destruction of neurones in the caudal part of medulla oblongata ventral portions after injection of 0.65 micrograms of kainate as soon as 30 min after injection was paralleled by a trend to increase of the blood serum levels of triiodothyronine and thyroxin-binding globulin, this increase attaining reliable values by day 7 after destruction, when the effects of operation stress levelled.

[Neurotransmitter balance in the CNS structure as effected by the combination of ionizing radiation and various doses of lead acetate].

In experiments with mature Wistar male rats exposed to 25- and 50-fold fractionated doses of external X-ray radiation (0.5 Gy) and daily probe-assisted administration of plumbum acetate (100, 10, 5 mg/kg), similar, but differently marked changes in transmitter relationship in some CNS structures resembling the earlier found neurotransmitter disbalance during chronic stress of different ethiology were revealed. Combined exposure to plumbum and radiation led to more sustained and prolonged disorders to transmitter relationship associated with a sharp decrease in specific binding of corticosterone in CNS glucocorticoid-sensitive structures.

[Function of the hypothalamus-thyroid system long after radiation and neurotropin correction of the disorders detected].

In experiments on Wistar male rats exposed to single X-ray radiation 0.5 Gy and combination of X-ray 0.5 Gy and 131I 6.

[Intracerebral connections after administration of kainate into the caudal part of ventral sections of the medulla oblongata].

It was found that 1 day after unilateral destruction with kainate of neurons in the caudal ventral medulla unanesthetized animals showed disorders of arterial pressure control with a prevalence of hypertensive response. In 7 days after operation there was a decrease in the rate of neuronal uptake of serotonin and an increase in choline-, dopamine-, noradrenaline-, and glycinergic mediation in the basal hypothalamus and rostral ventral medulla, which characterize the functional state of synaptic formations in the brain stem structures connected to neurons in the caudal ventral medulla and involved in cardiovascular regulation.

[Glucocorticoid control of the mediator process in the brain structures during immediate adaptation].

In male rats with a high and low blood levels of corticosterone, the activity of serotonin-, dopamine-, noradrenaline-, glycine, GABA-, and cholinergic processes was shown to depend on the glycocorticoid content in the organism and receptor binding of 3H-corticosterone in different brain structures. The formation of adequate processes of neurotransmitter adaptation to a short-term vibration is only possible at a fairly high level of glycocorticoids in the organism.

[Modifying effects of neurotropin on post-radiation disorders of neuromediator processes in the autonomic function regulation centers].

In experiments on Wistar rats, it was shown that 6 months after exposure to ionizing radiation (X-radiation 0.5 Gy and intraperitoneal 131I 6.5 mCu/kg) the hypothyroid state was accompanied by changes in inhibitory and excitatory mediation that are characteristic of chronic radiation stress in cerebral structures responsible for regulation of autonomic and animal functions and a relative deficiency of the hypothalamopituitary-adrenocortical axis.

[The role of glucocorticoids in the post-vibration changes in inhibition mediation in the brain structures].

Low-frequency vertical vibration for 2 hours together with three-fold increase of glucocorticoids is accompanied by the disruption of typical relationships of neuromediator processes (norepinephrine- and serotoninergic mediation) as well as the reduction of the intensity of choline trapping with glucocorticoid perception. Glucocorticoid-related conformation changes in plasma membranes and a drastic increase of the cAMP level provide plasticity of both nonspecific (hypothalamus, raphe bluish sites and nuclei) and specific (Deiters' nuclei) structures. The relationships of neuromediator processes in different CNS structures depend on the content of glucocorticoids.

[Mediator processes in the brain structures in the late periods after external and combined exposure to ionizing radiation].

In experiments with mature Wistar male rats it was shown that X-radiation of 12.9 mCi/kg and the combined effect of X-rays and 131I of 6.5 mCi/kg changed the rate of mediator processes in the structures responsible for the hypothalamic function regulation.

[Early effects of the influence of ionizing radiation in relatively small doses on the neuromediator systems responding to the central regulation of the hypothalamo-pituitary-adrenal cortex system].

In experiments with mature Wistar male rats changes of mediator interrelations in different brain parts, responsible for the central regulation of the hypothalamo-pituitary-adrenocortical system, were detected at early times after whole-body X-irradiation with a dose of 12.9 mC/kg. These changes represent one of the major mechanisms leading, at later times after irradiation, to the development of syndromes related to diencephalic disturbances.