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Biomedical subjects

N S Popova

Publications and source records attributed to N S Popova.

10 recordsLinked to original sources
PubMed1992

[Prolonged action of tuftsin in penicillin epilepsy].

The free behaviour experiments on rats showed during the first day the tuftsin-induced (0.3 mg/kg i. p.) increment of epileptic discharge in all the structures simultaneously. Open field behaviour depended on the sequence of penicillin and tuftsin injections. The rats with tuftsin used after the epileptiformic activity has been developed showed the behaviour analogical to the penicillin-injected animals. The preventive injections of tuftsin resulted in restoration of all behavioural indications by the third day. The optimal corrective effect has been obtained with tuftsin used preventively.

Animals↗
PubMed1979

[Decrease in the stress reaction and the ulcerative lesions of the stomach under the influence of gamma-hydroxybutyric acid].

The effect of preliminary Na gamma-hydroxybutyric acid (GHBA) injection on the activation of adrenergic and hypophyseal-adrenal systems during emotional-painful stress and ulcerous affection of the stomach after the stress cessation was studied in experiments on rats. It was established that the preliminary GHBA administration inhibits stimulation of stress causing systems and thereby prevents ulcerous affection of the stomach mucosa. It is suggested that the activation of GHBA-ergic inhibiting system, which accompanies the stress, is a natural mechanism of limitation of the stress reaction and prevention of the stress affections.

Animals↗
PubMed1978

[Changes in the content of eosinophils, corticosterone and catecholamines during liver regeneration following resection].

Experiments on albino rats demonstrated changes in the-blood eosinophil level, as well as in the content of catecholamines and corticosterone in the plasma, the adrenal glands, and the heart following partial hepatectomy. Phasic character of the hypophysis-adrenal system responses to resection and the processes of the liver regeneration was revealed, and this is reflected in the eosinophil level.

Adrenal Glands↗
PubMedDate not supplied

[Dynamics of evoked potentials in the auditory zone of the dog cerebral cortex following extirpation of the medial geniculate bodies during formation of goal-directed behavior].

Integrative processes in the auditory cortical zone were studied in three dogs by EEG and EP parameters during the formation of a defensive reaction to clicks (four clicks, two per second) after the extirpation of the medial geniculate bodies. In the operated animals information is transmitted to the cortical end of the auditory analyser by compensatory paths with a larger number of relays. In the auditory cortex EPs are recorded with a longer latency (12 to 16 msec), and the duration of the negative EP component is increased (up to 40 msec). It is split mainly on the ascending front. The cortical end of the analyser participates in the formation of processes of afferent synthesis. In the active period of reflex elaboration the inflow of information increases: the EP amplitude and the duration of its main negative component become greater (up to 45-55 msec), as well as the splits on its fronts. In the course of preparing for a decision, before the achievement of the conditioned reaction, a "double EP" appears, which is due to enhanced reverberation of excitations in the compensatory paths.

Animals↗
PubMedDate not supplied

[Dynamics of the statistical indices of evoked potentials in modally specific brain structures during the formation of defensive reflexes].

Interdependence of integrative processes in the relays of the analyzers of signal stimuli (auditory and visual) was estimated by EP parameters (latency, amplitude, and duration) of the first positive and negative components. It has been shown that the significance of the coefficients of correlation between EP parameters in the studied structures is determined by the stage of the behaviour formation; it also depends on the EP component chosen for the analysis. Significant correlation coefficients are timed to the active period in the formation of defensive conditioned reaction. In this period significant correlation coefficients for the parameters of the first positive EP component are established in various fields of cortical projection zones and between the parameters of the negative component in all relays of the analyzer. The data are treated from the viewpoint of adaptation of the analyser activity to the organism's needs at each stage in the formation adaptive behaviour and of the role of motivational influences in the organization of intraanalyzer integrations.

Adaptation, Physiological↗
PubMedDate not supplied

[Interrelationship between the auditory, parietal and sensomotor regions of the dog cerebral cortex during a defensive conditioned reflex].

Interrelations between projection (auditory), associative (parietal) and integrative-triggering (sensorimotor) cortical areas were studied in dogs by EP parameters and localization during formation of defensive conditioned reflex to clicks. These interrelations were studied in intact animals and after ablation of either T3 areas or PI2 area of the auditory cortex. It was found that in intact animals auditory cortical areas are constantly involved in brain integrations whereas parietal ones show periodical participation (EPs in the parietal cortical area accompany some pairings of signal stimulus with reinforcement). Integrative-triggering cortical structures are involved in the systemic processes in the period of stabilisation of defensive reaction. After ablation of T3 area integrative-triggering cortical structures are turned on within a large exitation system from the beginning of the defensive reaction formation. After ablation of PI2 area parietal areas constantly participate in brain integrations. The nature of their participation in the forming of a given functional system is determined by the state of the auditory system or location of its injury.

Animals↗