[Changes in the substance P content of the blood and hypothalamus during experimental emotional stress]. / Izmeneniia soderzhaniia substantsii P v krovi i gipotalamuse pri éksperimental'nom émotsional'nom stresse.

A study was made of the content of substance P in the blood and hypothalamus of Wistar rat brain in acute and chronic emotional stress and after intraperitoneal injection of substance P in a dose of 250 mg/kg. A possibility was demonstrated of inducing long-term changes in the content of substance P in the hypothalamus after a single injection. Exposure to a single 24-hour stress was followed by an increase in the substance P content in the hypothalamus.

[Self-stimulation reaction in normotensive and hypertensive rats]. / Reaktsiia samorazdrazheniia u normotenzivnykh i gipertenzivnykh krys.

The part of noradrenergic mechanisms in self-stimulation (SS) operant behaviour was studied in rats. In all experiments systolic blood pressure (BP) in the tail artery was measured by means of photocells. It was found, that small doses of noradrenaline facilitate the SS, while high doses depress or stop it. The depressive effect is accompanied by a marked increase of BP. Effective blockade of beta-adrenoceptive structures by inderal suppresses SS, and the inhibitory effect is accompanied by a small decrease of BP. Suppressing effect of alpha-adrenoblocking agent, phentolamine, is even more pronounced, but is accompanied by a marked decrease of BP. Beta-agonist isadrin causes a marked facilitation of SS without changes of BP. It is suggested that positive reward in the lateral hypothalamus is due to a direct stimulation of beta-adrenoceptive noradrenergic neuronal elements. Chronic neurogenic hypertension is developed by an overloading of the higher nervous activity. In chronic hypertensive rats there is a pronounced suppression of SS. A transient fail of BP caused by injection of catapresan (hemiton) results in a temporary recovery of normal SS behaviour. It may be concluded that reduction of lever-pressing rate during acute and chronic neurogenic hypertensions is related to baroreceptor mechanisms. The role of the autonomic nervous system in SS behaviour is discussed.

[Conditioned reflex, electrographic and mediator-humoral changes during intermittent hypokinesia of different duration in rats]. / Uslovnoreflektornye, élektrograficheskie i mediatorno-gumoral'nye izmeneniia pri preryvistoi gipokinezii raznoi dlitel'nosti u krys.

Intermittent hypokinetic stress in rats, lasting from 1 to 6 weeks was attended by a complex of shifts of behavioural, conditioned, bio-electrical and mediator-humoral parameters. They considered as an evidence of the changes occuring in the tonic level of emotional state. Different phases of emotional state follow one another with the progress of hypokinesia. Acute emotional stress is observed, as well as the development of a compensatory systemic reaction and initial symptoms of the exhaustion of adaptational systems.

[Changes in innate forms of motor behavior in rats during long-term hypokinesia]. / Izmenenie vrozhdennykh form dvigatel'nogo povedeniia u krys pri dlitel'noi gipokinezii.

The structure of motor behaviour in response to environmental tests--"open field" and "with-a-partner" situation (according to P. V. Simonov)--was studied in rats after 1, 3 and 6 weeks of hypokinesis, (to K. Hecht), as compared to the control. In control animals a relatively low level of orienting-investigation reactions and of grooming was observed as well as a low alimentary activity, which is considered as a manifestation of innate passive defensive reactions in the above situations. Disappearance of these reactions in the course of hypokinesia has two stages: predominant increase in orienting-investigating reactions (1-3 weeks); their subsequent decrease and an increase in the grooming (after 6 weeks). The relation between innate and conditioned behavioural changes is discussed as well as stability of alimentary behaviour in rats.