[Individual typological characteristics of hormonal responses in dogs during psychoemotional stress]. / Individual'no-tipologicheskie osobennosti gormonal'nykh reaktsii u sobak pri psikhoémotsional'nom stresse.

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. Blood cortisol and catecholamine levels were determined. Analysis of the result showed that an interaction takes place in the neostriatum between the corticoliberin and dopaminergic systems, and that in conditions in which dopaminergic structures are excluded, the efficacy of corticoliberin in the performance of behavioral acts decreases by 30-40%, i.e., complete expression of its regulatory role of motor situational conditioned reflexes is lost.

[Conditioning studies in the Pavlov's laboratory during 75 years of its existence (on the 150th birthday of Ivan Petrovich Pavlov)]. / Issledovaniia po uslovnym refleksam v pavlovskoi laboratorii za 75 let ee sushchestvovaniia (k 150-letiiu so dnia rozhdeniia Ivana Petrovicha Pavlova).

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.

[Striatal mechanisms of corticoliberin effect on the behavior of dogs with dopamine deficiency]. / Striatnye mekhanizmy deistviia kortikoliberina na povedenie sobak pri defitsite dofamina.

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. Studies demonstrated that while in dogs, most of the neurons recorded showed a transition to responses to the conditioned signal at a particular stage of carrying out a conditioned response, in monkeys all cells recorded showed specific responses at different periods of solving the task at all stages of the study. Neuropharmacological experiments on dogs showed that agents blocking glutamine receptors in the caudate nucleus had more pronounced effects at the phase of developing conditioned movement reflexes. Administration of these agents during the reflex reinforcement phase affected only the differentiation of inhibition. These results lead to the conclusion that the prefrontal area of the cortex and, to some extent, the caudate nuclei, act on incoming information specifying the current dominant need and the states of the external and internal environments, to carry out programmed actions and assess the results of these actions.

[The corticostriatal mechanisms of behavior]. / Kortikostriatnye mekhanizmy povedeniia.

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]. / Striato-nigro-talamicheskie mekhanizmy organizatsii povedeniia.

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.

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 thesis of the necessity of the coordinated functioning of the DA-reactive systems for the organization of goal-directed behavior is substantiated.

[The role of the dopamine-reactive systems of the cortex and neostriatum in organizing situational conditioned reflexes]. / Rol' dofaminreaktivnykh sistem kory i neostriatuma v organizatsii situatsionnykh uslovnykh refleksov.

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. / Aktivatsiia simpatiko-adrenalovoi sistemy vvedeniem kortikoliberina v khvostatoe iadro sobak.

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. Subsequent injections of corticotrophin releasing factor into caudate nucleus virtually did not change blood plasma catecholamine content, this indicating the participation of the strionigral complex dopaminergic structures in realization of corticotrophin releasing factor effect on the sympathoadrenal system.

[The localization of corticosteroid receptors in the dopaminergic structures of the canine brain]. / Lokalizatsiia kortikosteroidnykh retseptorov v dofaminergicheskikh strukturakh mozga sobak.

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.

[The administration of corticoliberin into the caudate nucleus activates the sympathetic-adrenal medullary and hypophyseal-adrenal cortical systems by different mechanisms]. / Vvedenie kortikoliberina v khvostatoe iadro aktiviruet simpatoadrenomedulliarnuiu i gipofiz-adrenokortikal'nuiu sistemy raznymi mekhanizmami.

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 neuroendocrine functions and behavior of dogs after corticoliberin administration into the caudate nucleus]. / Neiroéndokrinnye funktsii i povedenie sobak posle vvedeniia kortikoliberina v khvostatoe iadro.

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.

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. Switching off of the dopaminergic input makes the development of positive conditioned reflexes more difficult. The reversible switching off of the substantia nigra leads to the reorganization of the neuronal activity of the caudate nucleus in response to the presentation of the conditional signal. Inhibitory nigral influences are directed primarily to the ventromedial divisions of the nucleus, while activating influences are directed to its dorsal segments. The topically organized connections of the motor regions of the cortex with the dorsal region of the caudate nucleus, and of the limbic regions with its ventromedial divisions were studied in morphological investigations on cats. A certain distinctiveness was identified of the spatial organization of the nigrostriatal projections. The data obtained are discussed from the point of view from the systemic organization of behavior.

[The participation of the glutaminergic and dopaminergic systems of the neostriatum in the organization of conditioned food reflexes]. / Uchastie glutaminergicheskikh i dofaminergicheskikh sistem neostriatuma v organizatsii pishchevykh uslovnykh refleksov.

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.

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 results of the experiments with microinjections of the relevant substances into individual subcortical structures showed that activation of the same mediator system in various structures may lead to both unidirectional and multidirectional behavioral effects. On the other hand, the activation of various subcortical mediator systems can lead to identical changes in conditioned reflex activity. The effect of the administration of activators or blockers of a subcortical mediator system depends in many ways on the functional state of the nervous system at the moment of administration and on the localization of the microinjection. It is difficult to predict beforehand the role of various subcortical structures in the organization of integrated behavioral acts. The question of the necessity of studying mediator and peptidergic systems of each subcortical structure in order to understand their significance in the mechanisms of the conditioned reflex is raised.

[The participation of brain mediator and peptidergic systems in the mechanisms of the conditioned reflex]. / Uchastie mediatornykh i peptidergicheskikh sistem mozga v mekhanizmakh uslovnogo refleksa.

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.