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Biomedical subjects

T P Semenova

Publications and source records attributed to T P Semenova.

At least 19 recordsLinked to original sources

Seasonal effects of Selank on the behavior of hibernating animals.

We studied the seasonal effects of peptide preparation Selank on orientation and exploratory activity in 36 arctic ground squirrels Citellus undulatus in the open-field and hole-board tests. Selank most significantly increased behavioral activity of hibernating animals in the spring and fall. The test peptide had no effect on locomotor activity of animals. The selective stimulatory effect of Selank on exploratory behavior of hibernating animals was season-dependent. The maximum effect was observed under conditions of seasonal depression-like state.

Animals↗

Effects of L-thyrosyl - L-arginine (kyotorphin) on the behavior of rats and goldfish.

The effects of kyotorphin (KTP), a dipeptide (L-Tyr-L-Arg), on the level of sensory attention to stimuli of different modalities in rats and the exploratory behavior in goldfish were investigated. In both cases KTP was found to suppress the exploratory activity. When 5-HTP, a precursor of serotonin synthesis, is activated the inhibitory effects of KTP increased. It is assumed that the regulatory effect of KTP on the exploratory behavior of animals is mediated by the monoaminergic (neurotransmitting) brain systems, as distinct from its analgetic effects, which are mediated by the opioid brain systems.

5-Hydroxytryptophan↗

[Seasonal characteristics of the monoaminergic regulation of the behavior of hibernating animals].

The stimulating effect of L-DOPA on exploratory activity of the ground squirrel in the hole-board and open field experiments was stronger in the spring than in autumn, whereas the regulating effect of the 5-HTP on adaptive behaviour of hibernating animals was stronger in autumn. Results of the biochemical analysis of the MAO A activity with serotonin or noradrenaline as substrates revealed a seasonal dependence of the substrate specific changes of this enzyme activity in hibernating animals. The data obtained suggest that the seasonal distinctions in effects of similar pharmacological agents depend on activity of the brain monoaminergic systems' activity in hibernating animals in different periods of the annual cycle.

5-Hydroxytryptophan↗

[Effect of the preparation baliz-2 on the integrative brain activity and biogenic amine metabolism in rats under stress].

Effects of balis-2 on exploratory activity in the open field and elevated plus-maze, attention to sensory stimuli of different modalities, elaboration and retention of conditioned reflexes with food reinforcement, were studied in rats under stress. Prolonged treatment of rats with balis-2 seems to normalise integrative activity and metabolism of serotonine and dopamine in the animal brain.

Animals↗

[The role of serotonin in the effects of cholecystokinin-8 on memory in rats].

The HCK8 was found to inhibit the field search behaviour in rats. Administration of the peptide impairs formation and reproduction of a habit within 1 hour and 24 hrs. The data obtained suggest an important role of the brain monoaminergic systems in the mechanisms of the HCK8 effect upon learning and memory.

5-Hydroxytryptophan↗

Effects of 5-HT receptor antagonists on seizure susceptibility and locomotor activity in DBA/2 mice.

The effect of antagonists of serotonin (5-HT) receptor subtypes and alpha 2-adrenoceptors was investigated on audiogenic seizures and locomotor activity in DBA/2 mice. 5HT1c receptor antagonists (mianserin and cyproheptadine), 5-HT3 receptor antagonist (zacopride) and 5-HT4 receptor antagonist (ICS 205-930) increased the latency of audiogenic seizures and decreased the severity of convulsions in young (20-27 days old) DBA/2 mice. However, the effect of these antagonists varied in older (30-37 days old) mice. Ketanserin, 5-HT2 receptor antagonist, was devoid of any activity on audiogenic seizures. Yohimbine (0.5 mg/kg, i.p.), an alpha 2-adrenoceptor antagonist, increased the severity of audiogenic seizures, and the anti-convulsant effect of 5-HT receptor subtypes antagonists became more pronounced in the presence of yohimbine. 5-HT3 and 5-HT4 receptor antagonists produced hypolocomotor activity in young mice whereas 5-HT1c and 5-HT2 receptor antagonists were devoid of any effect on locomotor activity. Yohimbine did not induce any effect on locomotor activity but the mice exhibited more pronounced hypolocomotor activity following the administration of 5-HT3, 5-HT4 and 5HT1c receptor antagonists in the presence of yohimbine. However, the results varied with these agents in the older mice. These observations implicate a role of 5-HT1c, 5-HT3, 5-HT4 and alpha 2-adrenoceptors in audiogenic seizures in young DBA/2 mice, and 5-HT3 and 5-HT4 receptors in locomotor activity in these mice. Furthermore, these results also suggest an interaction between 5-HT receptors and alpha 2-adrenoceptors, and differential development patterns of various 5-HT receptor subtypes in the CNS.

Acoustic Stimulation↗

[The exploratory behavior in an open field and in a burrowing chamber of rats with different predispositions to stress].

The peculiarities of oriental research behavior and correlation between activities of catecholaminergic and serotoninergic brain systems dependently on their stress resistance degree were investigated in Wistar rats. The experiments showed that resistant (R) to a sound stimulus rats differed from nonresistant (NR) ones by increased research activity under moderate stress in the open field test and by decreased research behavior level in the cell chamber test. The biochemical analysis of biogenic amines in different brain structures revealed increased norepinephrine levels in stress R rats, and increased dopamine and serotonin levels in NR ones. The findings suggest that inborn behavior regulation in animals with different stress resistance is determined by different correlations between serotonin-dopamine and norepinephrine brain systems activities.

Animals↗

[Significance of the reciprocal relationship of monoaminergic systems of the brain in the pharmacological compensation of 6-hydroxydopamine-induced behavior disorders in animals].

The paper studied the methods of compensation of the abnormal emotional behaviour by means of pharmacological substances, which change the content of biogenic amines. The experiments made in the Wistar rats (n-54) whose frustration reaction was diminished by neonatal treatment of 6-OHDA. It was established that recovery of the disturbances in the frustration reaction in the animals with chronic brain system activity deprivation can be achieved not only by the activation of NA system (L-DOPA, DOPS) but also by deactivation of the 5-HT brain system activity (PCPA). These findings confirm suggestion about existence of reciprocal relationship between NA and 5-HT brain systems.

Animals↗

[Characteristics of the action of psychostimulants on learning and memory in rats].

The effects of intraperitoneal injections of psychostimulant drugs: centrophenoxine (50 mg/kg) and peptide analog of tuftsin TP-1 (300 micrograms/kg) on the processes of elaboration and retention of conditioned reflex have been experimentally studied. The animals were trained with food reward in 30 trials per day. Psychostimulant drugs or saline were injected after the 10th trial. The elaboration of conditioned reflex was continued 30 min later. The retention was tested 24 h, 7 and 30 days later. It was established that both drugs induce an increase in memory traces stability during 30 days. These findings provide direct evidence that psychostimulant drugs, centrophenoxine and peptide substance TP-1, when injected during consolidation phase can enhance memory storage processes.

Animals↗

Behavioural, biochemical and histochemical effects of locus coeruleus transplantation in rats with neurotoxic lesions of the catecholaminergic system.

Exploratory activity in the open field and noradrenaline concentration in the neocortex and brain stem were investigated in intact rats (n = 10) and in the following groups of rats with early postnatal neurotoxic (6-hydroxydopamine) lesion of the catecholaminergic system: (i) rats with embryonal locus coeruleus grafts in the frontal neocortex (n = 5); (ii) rats with the same grafts in lateral ventricles (n = 4); (iii) a control group with intracortical hippocampal tissue grafts (n = 3); (iv) sham-operated rats (n = 3). Experiments were performed by four independent groups of investigators using a double-blind method. In sham-operated rats as well as in rats with hippocampal grafts, and with locus coeruleus grafts in the ventricles, both exploratory activity and noradrenaline content of the forebrain were significantly lowered. In the rats with intracortical locus coeruleus grafts the level of exploratory activity was much higher (almost as in intact controls). This improvement of exploratory behaviour correlated highly with increased noradrenaline concentration in the forebrain. In all animals with locus coeruleus in lateral ventricles a significant increase in noradrenaline level of the brain stem was present, but no change of exploratory behaviour was observed. The grafts with the 3-mm-thick slabs of the adjacent tissue were dissected from the brain and used for histological analysis. The presence of typical locus coeruleus cells was shown in neocortex of all animals which received the grafts of corresponding tissue. The data show the possibility of stable compensation of the forebrain noradrenaline level and exploratory behaviour by embryonic noradrenergic neurons grafted into the neocortex, but not into lateral ventricles.

Animals↗

[Differences in the effects of 6-hydroxydopamine on rat learning with intraventricular and local administration into nuclei of the brain catecholaminergic system].

Correlation of the effects obtained with different routes of 6-hydroxydopamine (6-OHDA) administration to the rat brain on the training has disclosed that the drug injection to the lateral ventricles of the brain markedly interferes with the animals' learning both on food and painful reinforcement. Administration of 6-OHDA to the area where noradrenergic neurons have accumulated (A6) is followed by the embarrassment of active avoidance behavior and facilitation of the training on food reinforcement. Local administration of 6-OHDA to the area where dopaminergic neurons have accumulated (A9) decreases the reliability of the formed habits whatever the emotional sign of the reinforcing stimulant.

Animals↗