[Participation of NO-synthase system in the stress-mediated reactions of the brain].

Neurosis-like status developing as a result of the exposure of animals to chronic stress, which is associated with a transitory cerebral hypoxia, could cause significant structural and functional alterations in many brain structures. Realization of humoral stress effects on the brain is mediated by both extra- and intracelullar signal molecules, among which nitric oxide (NO) is considered to be one of the most potent ones. Expression of neuronal constitutive (nNOS) and inducible (iNOS) isoforms of NO-synthase was studied by immunohistochemistry in the neurons of albino rat brain after exposure of animals to chronic stress resulting in the development of neurosis-like status.

[Blood testosterone in rats: correlation with individual anxiety and its derangement after the "death threat"].

After preliminary testing on a multiparameter scale, test and experimental groups of Wistar male rats were formed on the principle of identical distribution of individuals with different anxiety levels. A negative Spearman correlation between the testosterone blood concentration and the level of anxiety was observed in intact rats: the minimum hormonal concentrations (lower than 5 nmol/l) were found in rats with high anxiety, whereas the maximum concentrations (up to 16 nmol/l) corresponded to the higher anxiety level (prevalence of passive defense reactions during testing). After a sort-term exposure to life-threatening situation (viewing of a boa's attacking and devouring two victim rats from the test group), the correlation was deranged because of appearance of a scatter in testosterone blood concentration (from 3 to 21 nmol/l) in rats with low anxiety.

[Neuroses and their pathogenesis].

History and current state of the problem of experimental neuroses are reviewed in this article. The presented results of neurochemical, structural, and electroencephalographic investigations unravel earlier unknown aspects of the disease. Thus, circulatory cerebral hypoxia, as a principally new stage discovered for the first time in the development of an experimental neurosis allows the pathogenetically substantiated treatment with antioxidants to be applied in animal experiments and in clinical therapy of neurotic patients.

[The influence of chronic neurotization on the monoaminergic systems of various brain structures in rats with various typological characteristics].

Typological behavioral features of Wistar rats were tested in the open field and in Porsolt test. Rats were assigned to groups with high (HAct), medium (MAct), and low (LAct) behavioral activities. The same rats were assigned to high (HDep), medium (MDep) and low depressive (LDep) groups.