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Biomedical subjects

N F Suvorov

Publications and source records attributed to N F Suvorov.

At least 19 recordsLinked to original sources
PubMed1998

[Striatal mechanisms of corticoliberin effect on the behavior of dogs with dopamine deficiency].

Interaction between dopaminergic and corticoliberinergic integrative systems in the process of situation alimentary conditioning, was studied in dogs with chemotrodes indwelled in the caudate nucleus head. Following the CRF administration, the cortisol and catecholamine levels were determined in the blood of intact dogs and in the dogs with 6-OHDA impairment of the substantia nigra. The findings suggest that an interaction between the CRF and dopaminergic systems occurs in the neostriatum.

Animals↗
PubMed1995

[The striatonigral-thalamic mechanisms in the organization of behavior].

Experiments in dogs with striatal deficiency revealed an important role of dopaminergic mechanisms in establishment of the situation conditioning. A rearrangement of the background unit activity of the caudate and thalamic nuclei preceding presentation of a conditioned stimulus and correlating with correct accomplishment of a motor task, was revealed in cats. Afferents from intralaminar and ventral nuclei of the thalamus were shown. Participation of striatal, nigral and thalamic levels in systemic organisation of motor conditioning is discussed.

Acoustic Stimulation↗
PubMed1995

[The corticostriatal mechanisms of behavior].

Experiments in dogs, cats and monkeys revealed that, along with the diffuse principle of afferent terminal arrangement within the striatum, there exist some features of terminal organisation by the anterior-posterior and medio-lateral gradients. The data obtained suggest that the prefrontal cortex and the caudate nucleus head maintain programming of intentions and the evaluation of performed actions.

2-Aminoadipic Acid↗
PubMed1993

[The administration of corticoliberin into the caudate nucleus activates the sympathetic-adrenal medullary and hypophyseal-adrenal cortical systems by different mechanisms].

The activation was revealed, through a considerable increase of levels of adrenaline, noradrenaline and cortisol. Corticotropin-releasing factor seems to act upon the sympatho-adrenal system (SAS) via dopaminergic mediation. The mechanisms of triggering of the SAS and pituitary-adrenocortical system by the corticotropin-releasing factor seem to be different and due to involvement of different extrahypothalamic structures in the regulating contours.

Adrenal Cortex↗
PubMed1992

[The neuroendocrine functions and behavior of dogs after corticoliberin administration into the caudate nucleus].

Within 30-60 min after corticoliberin administration into the dog caudate nucleus, a considerable activation of hypophyseal-adrenocortical system occurred. The motor behavior of the dogs also changed as well as their orienting behaviour, emotional tension, their blood pressure being elevated. Along with its effect on the adrenocortical function, corticoliberin seems to activate behavioural as well as vegetative processes by means of a direct action upon the caudate nucleus' neurons.

Animals↗
PubMed1990

[The participation of the glutaminergic and dopaminergic systems of the neostriatum in the organization of conditioned food reflexes].

Behavioural, neurophysiological and morphological experiments have shown specific influences of cortical and nigral inputs on the neostriatal functioning. The exclusion of cortical inputs resulted in different behavioural effects. Exclusion of nigral, dopaminergic input into the striatum led to impairment of conditioning. The unit activity data have shown that inhibitory nigral influences are mainly directed to the ventro-medial parts of the caudate nucleus, and activating ones--to the dorsal parts of this structure. Morphological studies have revealed topically organised connections of the motor areas of the cortex with dorsal parts of the caudate nucleus and limbic cortical areas with its ventro-medial parts. Some specifics of spatial organisation of nigral projections to the striatum have been shown. Experimental data are discussed in the light of systemic organisation of behaviour.

Animals↗
PubMed1990

[Errors in perceptive-motor activity as an index of a disorder in the processes of emotional self-regulation in neurotic patients with a high level of anxiousness].

Neurotic patients with high level of anxiety revealed a specific asymmetry of errors with prevalence of "false anxiety" as expressed by a tendency towards getting ahead of a moving marker on the screen. Reduced efficacy of the operator activity in neurotic patients is regarded as a consequence of a deficiency in the ability to suppress excessive emotional tension induced by involvement in the activity.

Adult↗
PubMed1989

[The participation of brain mediator and peptidergic systems in the mechanisms of the conditioned reflex].

In dogs with implanted chemotrodes and microelectrodes, the role of acetylcholine-, dopamine-, GABA- and P-ergic systems of the caudate nucleus and amygdala in positive and inhibitory conditioning, was studied. Activation of the same transmitter system in different structures could exert different behavioral effects, whereas activation of different transmitter subcortical systems could induce the same behavioral responses. The effects of activating or blocking agents upon the mediator subcortical system depended on the functional state of the nervous-system at the moment of administration as well as on the site of administration. It seems difficult to predict a contribution of one or another subcortical structure in organization of behavioral acts.

Amygdala↗
PubMed1989

[Avoidance conditioned-reflex behavior in rats chronically administered leucine enkephalin and its synthetic tetrapeptide analog into the neostriatum].

The three-week daily administration of 5 and 15 micrograms leu-enkephalin and its synthetic tetrapeptide analogue into the rat neostriatum led to an inhibition of avoidance conditioning in shuttlebox. Starting on the 10th day of the synthetic analogue injections, a motor excitation and a stereotyped behaviour were observed. No withdrawal effects were found. The tetrapeptide analogue was more effective than the natural leu-enkephalin in the same dose. A possible dopaminergic mechanism involved in the enkephalin long-term treatment, is discussed.

Animals↗
PubMed1988

Role of the caudate nucleus in performance of the conditioned reactions connected with sound localization.

The instrumental differentiation of left-right positions of sound-conditioned stimuli (series of clicks under dichotic stimulation) in 8 dogs was examined before and after the bilateral electrolytic lesions of various parts of the caudate nucleus (NCd). It was demonstrated that after damage of the NCd the correct differentiation of the side of monaural sound stimulation was preserved in all dogs. However, the differentiation of lateralization of sound produced by interaural time differences was selectively impaired. Lesions of the dorsal part of the NCd heads caused the absolute absence of the differentiation of the binaural sound image lateralization for 21-50 days after the operation. This function partially recovered but the percentage of correct responses remained significantly reduced in comparison with preoperative performance. Lesions of the ventral segment of the NCd heads of different parts of the NCd bodies had less influence on the performance of this behavioral task. In these cases there was no period of absolute absence of the differentiation, but the level of correct responses to the binaural signals was significantly reduced. It is suggested that the NCd is a part of the system of brain structures in which the parameters of the conditioned sound signals are compared with a reference system for recognition of sound location. The result of this comparison is used by the NCd for choosing a corresponding program of the motor response.

Animals↗