[Individual typological characteristics of hormonal responses in dogs during psychoemotional stress].

Effects of psycho-emotional stress on contents of steroid hormones in the blood were studied in dogs with different typological properties of the higher nervous activity. Under stress condition, a significant correlation between the cortisol and testosterone levels and the dogs' typological characteristics was found. The more obvious fluctuations in the hormones level occurred in animals with strong and excitable type of the nervous system as compared with dogs belonging to weak and inert type.

Striatal mechanism of action of corticoliberin on behavior in dogs in conditions of dopamine deficiency.

This report describes studies of the interaction of the integrative dopaminergic and corticoliberin systems in the neostriatum during performance of situational food-related conditioned reflexes. Studies were performed in dogs with chemotrodes implanted in the substantia nigra and the head of the caudate nucleus. 6-Hydroxydopamine was injected into the substantia nigra at a dose of 50 microg, and 10 microg of corticoliberin was injected into the caudate nucleus.

[Conditioning studies in the Pavlov's laboratory during 75 years of its existence (on the 150th birthday of Ivan Petrovich Pavlov)].

The paper reviews experimental and clinical data obtained on physiology and pathology of the higher nervous system by the Laboratory founded by I. P. Pavlov during 75 years of its existence: the principle of systemic organisation of the brain structures activity, the role of separate subcortical structures in organisation of behaviour, theoretical development of experimental pathology problems, inner inhibition, the role of sympathetic nervous system in conditioning, possible neurophysiological and neurochemical mechanisms of conditioning.

Voluntary movements and event-related potentials in Parkinsonians (stages 1-2).

The temporal analysis of goal-directed movements has revealed that the delay of movement initiation in Parkinsonians might be decreased or abolished by altering the preparatory set and increasing the motivation level of patients. Averaged event-related potentials (ERPs) during different psychomotor reactions to light stimuli, ignore condition and difference waves between attend (reactions) and ignore conditions were analyzed in 19 Parkinsonian patients (stages 1-2) and 12 healthy subjects. A deceleration of psychomotor reactions in the patients was found to be accompanied by a decrease in ERPs, especially in frontal recording.

[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.

Corticostriatal mechanisms of behavior.

This article presents the results of three series of experiments on cats, dogs, and lower primates, performed to investigate the structural, neurophysiological, and mediator mechanisms of the corticostriatal systems involved in the organization of behavior. Morphological studies of corticostriatal connections showed that along with the diffuse distribution of afferent terminals within the striatum, there were also elements of topical organization defined by anteroposterior and mediolateral gradients. Neurophysiological experiments on dogs and lower primates were used to study the spike activity of the prefrontal region of the cortex and the head of the caudate nucleus during training to conditioned first- and second-order reflexes and during the solution of complex problems involving delayed spatial selection.

[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.

[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.

Role of dopaminoreactive systems of the cortex and the neostriatum in the organization of situational conditioned reflexes.

The results of experiments on dogs with dysfunction of the dopaminoreactive system of the brain suggest the nonidenticality of its different divisions (cortical, striatal, mesencephalic) in the organization of situational conditioned reflexes. It was demonstrated that the nigrostriatal system is involved to a greater degree in the spatial analysis of signals, while the mesocortical system is more involved in the analysis of their biological significance. The dopaminoreactive system of the caudate nucleus is associated to a greater degree with the realization of cognitive, while that of the putamen is associated with the realization of motor programs of situational conditioned reflexes.

[The role of the dopamine-reactive systems of the cortex and neostriatum in organizing situational conditioned reflexes].

The nigrostriatal dopamine-reactive (DA) system was shown to participate more in spatial analysis of conditioned signals, whereas the mesocortical DA system was rather more involved in the analysis of the signals' biological significance in dogs. The DA system of the caudate nucleus was involved in realisation of cognitive programs rather, whereas the putamen's DA system--in realisation of the motor ones. The coordinated activity of different levels of the DA system seems to be necessary for organization of the goal-directed behaviour.

[Sympatho-adrenal system activation by administration of corticoliberin in the dog caudate nucleus].

Corticotrophin releasing factor injection into the head of the caudate nucleus of dogs was followed by a more than threefold increase of blood plasma adrenaline and noradrenaline levels as soon as in 30 min and by their reduction by the 60th min after the injection though not to the initial values. These changes are compatible to stressor reaction and are associated with an increased orientation research reaction in animals. Injections of 6-hydroxydopamine into caudate nucleus drastically exhausted dopamine content in this structure.

[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.

[The localization of corticosteroid receptors in the dopaminergic structures of the canine brain].

Dopaminergic structures of the dog brain were found to be able to specifically bind corticosteroid hormones. The data obtained suggest localisation of corticosteroid receptors on the terminals of dopaminergic receptors.

Participation of glutamatergic and dopaminergic systems of the neostriatum in the organization of alimentary conditioned reflexes.

In this study the results of behavioral, neurophysiological, and morphological investigations in relation to the participation of the corticostriatonigral system in the organization of conditioned reflexes are presented. It was demonstrated in experiments on dogs that blockade of N-methyl-D-aspartate receptors of the caudate nucleus disrupts the realization of consolidated conditioned reflexes and renders their development more difficult. The blockade of quisqualate receptors facilitates the process of differentiation.

[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.

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

New data on the significance of mediator and peptidergic systems of the striatal level in the organization of alimentary conditioned reflexes are presented in this report. The role of acetylcholine-, dopamine-, GABA-and P-ergic systems of the caudate nucleus and the amygdala in the realization of positive and negative conditioned reflexes was investigated. The experiments were carried out on dogs with chemotrodes and microelectrodes implanted in subcortical structures.

[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.