PubMed Health⌕ Search

Biomedical subjects

S V Verevkina

Publications and source records attributed to S V Verevkina.

17 recordsLinked to original sources
PubMed1994

Effects of stimulation of the frontoparietal cortex and parafascicular nucleus on locomotion in rats.

The spontaneous motor activity and locomotion initiated by electrical stimulation of the lateral hypothalamus were recorded after electrical stimulation (50-500 microA, 10-30 Hz, 0.1 ms pulses) of the frontoparietal cortex (FrPaM) and parafascicular nucleus of the thalamus (PF). Local injection of kainic acid (KA) (0.02 micrograms, 1.0 microliter) was applied to the FrPaM and PF to avoid stimulation of descending fibres of passage. The electrical stimulation and KA application to the FrPaM and PF produced inhibition of locomotion in freely moving rats. In Nembutal-anesthetized (25-30 mg/kg) rats electrical stimulation of the FrPaM and PF inhibitory zones blocked the increase of phasic and tonic electrical activity of hindlimb muscles elicited by electrical stimulation of the lateral hypothalamus (LH) and red nucleus (R). Electrolytic lesion of inhibitory zones of the raphe magnus nucleus (RMg) and adjacent areas of gigantocellular (Gi) reticular nuclei arrested blocking effects of the FrPaM and PF on motor activity and hindlimbs tonus. The results demonstrated a possible role of the FrPaM and PF in initiation of locomotor activity inhibition. Interactions of the FrPaM and PF with the brain stem inhibitory zones are also discussed.

Anesthesia↗
PubMed1991

[The effect of microinjections of vasopressin into the inhibitory centers of the brain stem on rat behavior].

Microinjection of the arginin-vasopressin into the medial parabrachial nucleus, n. cuneiformis, raphe median nucleus and raphe magnus nucleus suppressed spontaneous locomotor activity and orienting response to electrical stimulation of hypothalamus in rats. Microinjections of 5,6-dihydroxytriptamine in n. raphe magnus blocked the inhibition of behaviour elicited by vasopressin.

5,6-Dihydroxytryptamine↗
PubMed1990

[The effect of brain stem structures on the formation of defensive behavior in animals].

Electrical lesions of the nucleus cuneiformis, parabrachial medial nucleus, nucleus raphe median and the nucleus raphe magnus induce an active response of defence. Local microinjections of kainic acid in these sites result in a contrary effect. The findings suggest that inhibitory locomotor system of the brainstem may influence the formation of defensive behaviour in rats.

Aggression↗
PubMed1990

[The central neurophysiological mechanisms in the regulation of inhibition].

Electrical and local chemical stimulation of the n. cuneiformis, the parabrachial medial nucleus, the n. raphe median and the n. raphe magnus induces an inhibition of locomotor activity in rats. Changes of the legs' flexor and extensor muscles' tone followed electrical stimulation of the inhibitory zones. Lesion of the n. n. median and magnus raphe blocks the inhibitory effects of electrical stimulation of the n. cuneiformis and the parabrachial medial nucleus.

Animals↗
PubMed1988

[Neurochemical mechanisms of regulation in cataleptiform states in animals].

Influence of serotonin- and GABA-ergic systems on cataleptic responses to electrical stimulation of the medial parabrachial nucleus, cuneiform nucleus, median and magnus raphe nuclei, was investigated in chronic experiments on rats. The brainstem structures seem to form a morphofunctional inhibitory system participating in catalepsy.

Animals↗
PubMed1987

[Various mechanisms of action of vasopressin on animal behavior].

Microinjection of the arginine-vasopressin into the caudal ventrolateral area of the brain suppressed locomotor activity and orienting response to electrical stimulation of hypothalamus in rats. Microinjections of the peptide into the corticomedial amygdala increased spontaneous locomotion and genital grooming. The data obtained suggest a selective influence of vasopressin on different areas of the brain.

Amygdala↗
PubMedDate not supplied

Influence of brain stem structures on the formation of the defensive behavior of animals.

The dependence of the dominant form of the defensive behavior of white male mongrel rats on the functional state of the brain stem inhibitory locomotor system has been studied in chronic experiments. It was established that the electrolytic destruction of the inhibitory zones of the cuneate nucleus of the midbrain, the medial parabrachial nucleus, the central and great nuclei of the raphé leads to the dominance of active defensive reactions in animals in confrontations with partners. The opposite effect is exerted by local injection of kainic acid into these regions of the brainstem. It is hypothesized that the functional state of the brain stem inhibitory locomotor system can exert a modulating influence on the formation of the defensive behavior of animals.

Animals↗
PubMedDate not supplied

Some mechanisms of action of vasopressin on animal behavior.

The effect of arginine vasopressin on the behavior of rats after its microinjection into the caudal ventrolateral region of the brain stem and corticomedial amygdala was investigated. In the region of the brain stem vasopressin has a predominant inhibitory effect of motor activity and orienting behavior evoked by electrical stimulation of the hypothalamus. In the region of the corticomedial amygdala under the effect of the peptide an alternation of motor inactivation with orienting reflexes, grooming, and genital genital grooming is observed. In this case an increase of the spontaneous frequency of neuronal impulses occurs in the investigated regions of the brain.

Amygdala↗
PubMedDate not supplied

Analysis of neuronal processes in activating systems of rat brain during development of the instrumental defense reflex.

We have developed a conditioned defense reflex in chronic experiments with rats using electrodes implanted in the reticular oral pons nucleus, the corticomedial group of amygdalar nuclei, the ventromedial hypothalamic nucleus, and the central gray matter of the midbrain. We showed that the synchronization of the activity of neuronal groups of emotiogenic formations of the brain structures investigated was enhanced during formation of the conditioned reflex. We established a dependence of the correlation of the activity of limbic neuronal groups on the functional state of the reticular formation, and also neurochemical correlation mechanisms. We were able to show that an increase/decrease in the coefficients of mutual correlation of the activity of the neuronal aggregates of limbic structures is accompanied by a change in the parameters of the evoked potentials recorded in them.

Action Potentials↗
PubMedDate not supplied

[An analysis of the neuronal processes in the activating brain systems of the rat during the acquisition of an instrumental defense reflex].

In chronic experiment, a defensive conditioned reflex was elaborated in rats with electrodes implanted in the reticular oral pons nucleus, cortico-medial group of amygdalar nuclei, ventromedial hypothalamic nucleus and central grey substance of the midbrain. Synchronization of the activity of neuronal groups of emotiogenic formations in the studied brain structures, became enhanced at formation of the conditioned reflex. A dependence was revealed of the level of correlation of limbic neuronal groups activity on functional state of the reticular formation, as well as neurochemical correlation mechanisms. The increase (decrease) of coefficients of correlation of the activity of neuronal ensembles of limbic structures was accompanied by a change of evoked potentials parameters recorded in them.

Animals↗