[Changes in psychophysiological variables in students during examinations].

Current psychological tests and classic methods for recording and calculating autonomic correlates were used to study changes in students' psychophysiological indices during examinations. During this period, the students were found to develop emotional stress characterized by a complex of psychophysiological and autonomic changes. The nature and direction of the latter were determined by the individual and typological properties the examinees, by the significance of the emotional and stress situation of the autonomic nervous system and its responsiveness.

[The neuronal organization of the limbic (cingulo-)-visceral reflex arc].

The paper summarizes new electrophysiological data concerning the structural-functional organization of the limbic cortex and role of the rostral limbic region of visceral functions. Here are presented the results of a series of electrophysiological investigation of the focus of localization in the supracallosal (area 24) and infracallosal (area 25) part of the anterior cingulate gyrus of evoked potentials of maximal amplitude and minimal latent period to stimulation of pelvic, splanchnic and sciatic nerves. It was shown that evoked potentials of maximal amplitude and minimal latent periods to stimulation of viscero-somatic nerves are recorded in the supragenual area 24 in comparison with the infragenual area 25 of the anterior limbic cortex.

[The role of the thalamic ventrolateral nucleus in the cortical effect on the activity of vestibular neurons].

Electrocoagulation of lateral vestibular nucleus (NVL) reduces inhibitory effect of the motor and somatosensory areas and enhances the inhibitory effect of limbic, vestibular, and orbital cortical areas. Facilitating effect was enhanced by electrostimulation of the motor area and reduced by the stimulation of other cortical areas. Following the coagulation of the NVL, the ascending afferent flow to the cortex seems to be reduced.

[A comparative analysis of the descending projections of areas 5 and 7 of the parietal cortex to the cat brain stem].

Relative quantity of descending fibres of parietal fields 5 and 7 of cat brain stem was studied. Maximal projections of these field were determined, maximal projections of fields 5 and 7 to red nucleus reticular nucleus of midbrain and nucleus proprius of pons were shown. Topographic and quantitative overlapping of projections of fields 5 and 7 in red nucleus and reticular nucleus of midbrain was noted.

[The role of various parts of the amygdaloid complex in the regulation of activity of respiratory neurons].

In microelectrophysiological investigations influences of different nuclear regions of the amygdaloid complex on the spike activity of the functionally identified single respiratory neurons of the medulla oblongata were studied in anesthetized cats. It was established a qualitative different character of the changes of unit activity of the medullary respiratory neurons in case of stimulation of phylogenetically old corticomedial or new basolateral nuclear groups of the amygdala. It was shown higher reactivity of the investigated neurons to stimulation of the corticomedial nuclei than basolateral.

[Effect of mediodorsal thalamic nucleus on the respiratory neurons from medulla oblongata and the rat respiration during hypoxia].

In the normal as well as in the oxygen deficiency conditions the research has been conducted to study the influence of associative mediodorsal (MD) nucleus of thalamus on impulsive activity of respiratory neurons of medulla oblongata of respiration. In conditions of normal atmospheric pressure, before the uplift of the animals, the electrical stimulation of MD of nucleus of thalamus has had mainly inhibiting influence. In the initial phase, on 4-5 thousand meter altitude, activation of frequent discharge of neurons occurred, the respiration has become frequent as well.

[Involvement of amygdala central nucleus in the regulation of cardiovascular functions].

Effects of high frequency stimulation of the amygdala central nucleus involved a selective decrease in the activity: an increase in the activity of the inferior cardiac nerve and a simultaneous decrease in the activity of the vertebral nerve, as well as an obvious BP increase. Bilateral electrolytic lesions of the same amygdala structure accompanied with an overload of the higher nervous activity induced no hypertensions. The role of the amygdala central nucleus in control of cardiovascular functions is discussed.

[Neuron mechanisms of the regulation of bulbar vagosolitary activity by structures of basolateral amygdala nuclei in cats].

Neuronal reactivity to single stimuli applied to both the peripheral nerves and the cortex, was the same in the cat solitary tract nucleus. The 1-20 Hz stimulation frequency rendered the reactivity either tonic in character or with reduced firing rate. A high degree of convergence (80.

[Response of the hypothalamic neurons to stimulation of the vestibular nerve and lateral vestibular nucleus in rabbits].

Effects of single, double, and rhythmic stimulation upon hypothalamic neurons responding to the 1st excitatory phase of lateral vestibular nucleus stimulation, were studied. The data obtained show that activation of some hypothalamic neurons following stimulation of the lateral vestibular nucleus has a monosynaptic character. The findings suggest that ascending afferents from the lateral vestibular nucleus to the hypothalamus pass via oligo- as well as polysynaptic pathways.

[The hypothalamic regulation of the activity of vestibular neurons during exposure to vibration].

In acute experiments in rabbits the influence of stimulation of the ventromedial hypothalamic nucleus on the activity of neurons of vestibular Deiters' nucleus was studied under conditions of 15-day exposure to vibration (60 Hz, 0.8 mm, 3 h daily). The mechanisms are discussed which underlie the observed phenomena.

[The effect of stimulation of the amygdala basolateral nuclei on the neuron activity of Deiters vestibular nuclei in rabbits].

A modulating character of the amygdala basolateral nuclei effect upon the vestibular sensory system was determined in rabbits [correction of rats]. A mechanism of the descending effect of the amygdaloid complex on the activity of the Deiters nucleus neurons, is discussed.

[The influence of the limbic cortex and hypothalamus on the impulse activity of the bulbar respiratory neurons and on respiration under hypoxia].

The response of bulbar respiratory neurons and the total inspiration to stimulation of the limbic cortex and hypothalamus was not identical as a result of different sensitivity of the studied structures. The hypothalamus exerts mainly facilitating influence both in norm and at the maximal altitude (7500-8000 m). The limbic cortex exerts mainly inhibitory influence.

[The neuronal organization of the amygdala-visceral reflex arch].

The paper summarizes the histomorphic, histochemical, autoradiographic, immune-histochemical and electrophysiological data on the structural-functional organization of the amygdalar complexes. While discussing the problem of neuron organization of the afferent and efferent groups in the amygdala-visceral arch the authors present their data of microelectrophysiological studies of the specific amygdala neuron reactions in response to stimulation of the vagus, ventric, and sciatic nerves, and of the second somatic sensor cortex zone. It was observed that interoceptive impulsation reaching the polysensor neurons of the central, corticomedial, and basolateral groups of the amygdala complex nuclei have no significant qualitative differences.

[Correlation of changes in the electrical activity and indices of tissue respiration of brain structures in rabbits exposed systematically to vibration].

The electrical activity and tissue respiration of the cortex and subcortex (posterior hypothalamic nucleus, Deiters' vestibular nucleus) have been studied in the rabbits during 3-month exposure to vibration (60H2, for 3h daily). On days 15-30 of exposure to vibration the electrocorticogram demonstrated the prevalence of alfa-waves whereas in the subcortex the teta-waves were dominated. On long-term vibration exposure (2-3 months), the synchronized slow waves were recorded on the EEG.

[The effect of stimulation of the orbitofrontal cortex on the activity of the bulbar respiratory neurons and on respiration in normal rats and in hypoxia].

Stimulation of the orbito-frontal cortex inhibited activity of bulbar expiratory, inspiratory and reticular (non-respiratory) neurons. The first phase of hypoxia generated facilitatory influence of cerebral activating structures, whereas the second phase led to a contrary effect (depression). Subcortical activating structures, however, retained some of their facilitatory influence thus maintaining the oxygen homeostasis of the organism.

[Cortical mechanisms of regulation of neuron activity of Deiters vestibular nucleus during vibration].

The peculiarities of the effect of vestibular, somatosensory, motor and limbic areas of brain cortex on the activity of neurons of lateral vestibular nucleus (LVN) are studied in the nembutal and chloralose anesthetized rabbits by the extracellular lead method before and after vibration exposure. It is found that the responses of neurons of Deiters's nucleus at all frequency ranges to stimulation of different areas of the cortex were predominantly of inhibitory type, being more pronounced during stimulation of the vestibular and motor areas. The facilitating corticofugal effect was noted in 20-30 % of cells and more pronounced influence was during stimulation of somatosensory and limbic areas of the cortex.

[The characteristics of the neuronal organization of the sympathetic-activating and sympathetic-inhibiting mechanisms of the visceral area of the limbic cortex].

Effects of high frequency stimulation of dorsal and ventral regions of anterior area 25 of the limbic cortex on the tonic electrical activity of two postganglionic sympathetic nerves of stellate ganglion-inferior cardiac and vertebral nerves and arterial blood pressure were studied in anesthetized cats. It was revealed three types of medullary influences: generalized activation of both sympathetic nerves and pressor responses mainly in case of stimulation of ventral structures, generalized inhibition of electrical activity of both sympathetic nerves and depressor responses in case of stimulation of dorsal region of area 25 and selective modulation of activity, namely increase in activity of inferior cardiac nerve and simultaneous decrease of activity of vertebral nerve. According to data of our previous comparative studies of sympathetic responses of inferior and vertebral postganglionic nerves to stimulation of anterior and posterior hypothalamus as a working hypothesis it is supposed that the dorsal region of area 25 of limbic cortex is the analogy of trophotropic system of anterior hypothalamus, the ventral region--of ergotrophic system of posterior hypothalamus.

[The role of the limbic cortex in regulating the neuronal impulse activity of the respiratory center in the medulla oblongata under conditions of oxygen deficiency].

Complex action of hypoxia and electrostimulation of the limbic cortex on unit activity of bulbar respiratory neurons was studied. Under normal barometric pressure the influence of the limbic electrostimulation on activity of bulbar respiratory neurons was ambiguous, i.e.

[The role of the paraventricular hypothalamic nuclei in the development of chronic neurogenic hypertension and the formation of a self-stimulation reaction].

Effects of bilateral electric lesion of the hypothalamic paraventricular nuclei on cardiovascular components of the defense response and on the self-stimulation operant behaviour, were studied in rats. Overloading of the highest nervous activity induced no hypertension in these animals, though the self-stimulation frequency increased.

[The neurochemical mechanisms of the influence of the posterior hypothalamus on the electrical activity of the forebrain hemispheres and on autonomic reactions in hens].

Effects of i.v. administration of N- and M-cholinergic blocking agents ganglerone and atropine and alpha- and beta-adrenergic blocking agents phentolamine and obsidan (propranolol) on reaction of desynchronisation of EEG and on autonomic reactions (arterial blood pressure, heart and respiratory rates) evoked by low- and high frequency stimulation of the posterior hypothalamus were studied in hens.

[Effect of hypothalamus and amygdala on the impulse activity of neurons of the medullary respiratory center in rats during hypoxia].

Investigations into the role of the hypothalamus nuclei (dorsomedial and posthypothalamic) and amygdala (cortical and central) in regulation of impulse activity of medullary respiratory neurons and respiration as a whole revealed: a) phasic changes of there exponents in hypoxia; b) variety effect of excitation (activation, inhibition) due to stimulation of the structures. At the initial stage of hypoxia (the altitude of 4000-5000 m) hypoxic activation of the impulse discharge made moderating effect of stimulation more expressed as compared with the initial stage of hypoxia. At maximal altitudes (7500-8000 m) inhibition of respiratory neurons occurred and respiration grew slow and superficial.

[The reactions of the viscerosensory neurons of the nucleus solitarius to stimulation of the posterior and anterior hypothalamus].

The "vagal" neurons of the solitary tract nucleus responded to stimulation of anterior and posterior hypothalamus in 78.7 and 27.6 per cent, resp.

[The reaction of the respiratory neurons of the medulla oblongata to stimulation of the amygdaloid complex nuclei in hypoxia].

Under atmospheric pressure, stimulation of amygdala induced an activating effect on the medullary respiratory and reticular neurons. At the initial stage of hypoxia (altitude 4000-5000 metres), against the background of hypoxic activation of the firing rate, facilitating influence of tetanic stimulation of the amygdala was lesser even though prevailing over its inhibiting action. At the maximal altitude (7500-8000 m), against the background of hypoxic suppression of unit activity, the stimulation of amygdala exerted mainly an activating effect.