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I V Nesterova

Publications and source records attributed to I V Nesterova.

50 records · Page 3Linked to original sources
PubMedDate not supplied

[The behavioral and biochemical sequelae of the removal of the olfactory bulbs in C57Bl/6j mice].

Ablation of the olfactory bulbs in mice C57Bl/6j was accompanied by motor and orienting-exploratory activity augmentation in the "open field" test and deterioration of the learning ability to active and passive avoidance. The most expressed behavioural changes developed in four weeks after the surgery. Chronic administration of antidepressants (amitriptyline, 20 mg/kg; trazodone, 20 mg/kg; imipramine, 10 mg/kg; intraperitoneally) normalized behaviour of bulbectomized animals, trazodone being the most effective. In the biochemical studies the brainstem serotonin level was found to be decreased and the density of 5HT2-receptors in the cerebral cortex increased in bulbectomized mice. Only trazodone was able to correct the biochemical indices. The state of the bulbectomized mice is supposed to serve a model of a depression with hypo-function of serotonergic system of the brain.

Amitriptyline↗
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[Primary visual cortex response recovery cycles caused by pharmacologic and electrical effects on the monoaminergic systems of the rat brain].

The recovery cycles (RC) of primary responses in the visual cortex were studied in alert rats following the electrical stimulation of raphe nuclei and locus coeruleus as well as following pharmacological and complex (electrical and pharmacological) actions on serotonin- and noradrenergic brain systems. It was found that both electrical and pharmacological actions on the above monoaminergic systems reduce the duration and depth of relative non-reactivity phase of RC. Complex (electrical and pharmacological) action leads to heterodirectional changes in RC. The character of these changes reflects the reciprocity existing in functional interrelations between serotonin- and noradrenergic brain systems. The probable connection of the found effects with memory mechanisms is discussed.

5-Hydroxytryptophan↗
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[Compensation in behavioral disorders in rats receiving 5,7-DHT neonatally and by transplantation of embryonic raphe nucleus tissue].

In 62 male Wistar rats the influence was studied of the transplanted embryonal tissue of raphe nuclei (NR) on the mechanisms of compensation of disturbances of exploratory activity, sensory attention, learning and emotional reactivity induced by neonatal injection of 5,7-DHT. In histochemical studies by Falk-Hillarp method the presence of yellow fluorescence confirmed the specificity of transplanted 5-HT neurones. It is found that NR transplantation causes in animals after 3 months recovery of orienting reaction to sensory stimuli, reduces rats reactivity in the open field, restores the ability to discrimination of emotionally positive influence, disturbed by neonatal injection of 5,7-DHT. The obtained data show the possibility of compensation of behaviour disturbances caused by chronic deprivation of 5-HT system activity by transplantation in the neocortex parenchyma of the embryonal tissue, containing serotoninergic neurones.

5,7-Dihydroxytryptamine↗
PubMedDate not supplied

[The effect of 6-hydroxydopamine on the behavior of rats with differing resistance to stress exposure].

The influences of 6-OHDA (150 mcg intraventricular, bilaterally) on the behaviour of Wistar rats with different resistance to sound-stress were studied. Reduction of reactivity, exploratory activity and learning deterioration after 6-OHDA administration were observed. The behavioural disturbances were more demonstrative in stress-resistant rats. Biochemical estimations showed that 6-OHDA induced a reduction of brain noradrenaline level in stress-resistant rats and a reduction of dopamine level in nonresistant animal. It is suggested that more demonstrative behavioural disturbances induced by 6-OHDA in stress-resistant rats are connected with deficit of brain noradrenaline.

Acoustic Stimulation↗
PubMedDate not supplied

[Effect of the local administration of 5,7-DHT and 6-OHDA into the neocortex on the learning and exploratory behavior of rats in an open field].

On Wistar rats characteristics were studied of investigating behaviour in the open field, of learning of conditioned food-reinforced reaction and also of BA and their metabolites content in various brain structures under local intracerebral injections of specific neurotoxins; 6-hydroxydopamine (6-OHDA) and 5,7-dihydroxytryptamine (5,7-DHT), abolishing correspondingly catecholaminergic and serotoninergic terminals. Bilateral injection of 6-OHDA in the neocortex led to a weakening of rats investigating activity in the open field and to an increase of the time of fulfillment of the forming of conditioned food-reinforced reaction. Administration of 5,7-DHT was accompanied by an increase of the investigating behaviour in the open field and a reduction of the duration of the forming of conditioned reaction. Administration of 6-OHDA to the neocortex caused a lowering of catecholamines level in the frontal area of the neocortex and the hippocampus. Analogous administration of 5,7-DHT elicited simultaneously with a deep level lowering of 5-HT and its metabolite in these structures, a change of catecholamines content which testifies to a lesser specificity of the neurotoxin 5,7-DHT in comparison with 6-OHDA. Structures lesion of serotoninergic and catecholaminergic systems of the frontal cortex and the hippocampus brought about by a local administration of 6-OHDA and 5,7-DHT in the neocortex was accompanied by differently directed changes in animals behaviour.

5,7-Dihydroxytryptamine↗
PubMedDate not supplied

[Role of the hypothalamus in originating disorders of exploratory behavior and learning in rats with excised nuclei of the locus coeruleus].

Open-field behaviour and emotionally differently reinforced learning were studied in male Wistar rats with bilaterally ablated Locus coeruleus. Histochemical analysis of the hypothalamic structures was carried out. Decrease of investigating activity and attention was found as well as disturbances of learning with emotionally-negative (painful) reinforcement. By means of histochemical methods, fluorescence characteristic for catecholamines was found to decrease sharply in paraventricular and supraoptic hypothalamic nuclei, eminentia medialis and the posterior lobe of the hypophysis.

Animals↗
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[Compensation for behavioral disorders caused by 6-hydroxydopamine administration via the transplantation of embryonic tissue from the locus coeruleus in rats].

Neonatal injection of 6-OHDA produces defects of sensory attention and emotional reactions in the rats. Possibility of compensation of these behavioural defects by the grafts of embryonal locus coeruleus (LC) tissue into the neocortex was investigated in male rats of the Wistar strain. Histological analysis revealed spindle-shaped and oval cells typical of LC in the neocortex of all animals with LC grafts. Characteristic green fluorescence of these noradrenergic cells was demonstrated by Falck's method. Normalization of the orienting reaction to sensory (tactile and visual) stimuli, as well as of frustration effects was observed in the animals with LC grafts, but not in the control groups with saline injections or hippocampal grafts. The data show the possibility of stable compensation of the behavioural defects resulting from neonatal injection of 6-OHDA by the grafts of embryonal tissue containing noradrenergic neurones.

Animals↗
PubMedDate not supplied

[Effect of damage to the serotonin- and noradrenergic systems of the brain on alimentary and defensive conditioned reflexes in rats].

A study was made on 79 Wistar male rats of the influence of destruction of single nuclei in the brain serotonin- and noradrenergic systems on their learning with alimentary and pain reinforcements. Electrolytic lesion of the raphe dorsal and medial nuclei hindered the formation of alimentary conditioned reflexes, while facilitating the elaboration of a conditioned active avoidance reaction. Destruction of the locus coeruleus was attended with improved alimentary learning, while the elaboration of conditioned active avoidance reaction proved to be more difficult as compared with that in the control animals. A conclusion is drawn that the nature of the influence of local ablation of individual nuclei in the brain serotonin- and noradrenergic systems on animals' learning is determined by the emotional sign of the reinforcing stimulus.

Animals↗
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[The role of the mammillary complex in consolidating memory traces].

The influence of the mammillary complex and of some other hypothalamus areas on the formation of a trace conditioned defensive reflex and EEG-reflex to time was studied in 19 rabbits with electrodes implanted in the brain. A transient functional switching off of the mammillary complex immediately after each learning session prevented formation of both reflexes. Simular procedures 2.5 to 3 hours after learning session did not affect the rate of reflex formation as compared with the control group of animals. Participation of the mammillary complex in the consolidation of memory traces has been suggested.

Animals↗
PubMedDate not supplied

[A change in the spontaneous and evoked activity of rabbit visual cortex neurons upon stimulation of different regions of the hypothalamus].

The influence of stimulation of different hypothalamic areas on spontaneous and flash evoked electrical activity of visual cortex neurones was studied in acute experiments on rabbits by means of extracellular records. Stimulation of most parts of the hypothalamus depressed both kinds of neural activity. Stimulation of the ventro-caudal part of the lateral hypothalamic area and the supramammillar area alone resulted in a pronounced facilitation of the cortical unit activity. Localization of the facilitating areas coincides with the zones of maximum positive reinforcement in selfstimulation. The data are discussed in relation to the mechanisms of motivational behaviour.

Animals↗
PubMedDate not supplied

[The role of the catecholaminergic innervation of the neocortical frontal area in regulating the behavior of rats with differing resistance to acoustic stress].

Influence of 6-OHDA (40 mcg) injection in the frontal neocortex on behaviour was studied in Wistar rats with different resistance to sound-induced stress. Reduction of exploratory activity in the open field, reactivity to stimuli of different modality and deterioration of food-procuring conditioning were observed after 6-OHDA treatment of stress-resistant rats. On the contrary, treatment of non-resistant rats with 6-OHDA increased the reactivity to stimuli of different modality and the learning capacity. Thus, catecholaminergic system of the frontal neocortex is differently involved in the regulation of cognitive processes in stress-resistant and non-resistant rats.

Acoustic Stimulation↗
PubMedDate not supplied

[Neutrophil granulocyte function in an acute experiment with cyclophosphane].

Experiments of mice F1(CBAx57BL) were made to study cyclophosphamide effects on the number of circulating neutrophil granulocytes (NG) and on their main functions (receptor, phagocytic, function of microbicidal systems). NG count, the number of NG carrying receptors to sheep red cells, complementary EAC=POH, phagocytic and digestive activities and NBT-test were measured 15 and 60 min after administration of small (0.5 mg/kg) and large (150 mg/kg) doses of cyclophosphamide. The results suggest clear dose- and time-related effect of the drug which can induce both depression and stimulation. The data obtained can be utilized in developing approaches to prevention of complications caused by NG dysfunctions in immunosuppressive therapy of tumors, lymphoproliferative diseases, organ and tissue transplantation.

Animals↗