[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.

[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 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.

[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.

Receptor binding of glutamate in the striatum of rats differing in learning capacity.

A comparative investigation has been carried out for the first time of the receptor binding of glutamate with synaptic membranes and coarse fractions of the postsynaptic enlargements isolated from the striatum of rats differing in their capacity to develop an alimentary instrumental reflex. It was demonstrated that the number of that glutamate binding sites on the postsynaptic enlargements isolated from the striatum of rats capable of rapidly developing an alimentary instrumental reflex was increased as compared with animals not subjected to training. This relationship is maintained two months after the termination of training.

[The conditioned reflex behavior of dogs to the intracaudate administration of corticoliberin]. / Uslovnoreflektornoe povedenie sobak pri vnutrikaudatnom vvedenii kortikoliberina.

Situational conditioned reflexes in dogs were studied before and after intracaudate bilateral microinjections of corticoliberin (CRF). Intracaudate microinjections led to an enhancement of locomotor activity, the restoration of earlier extinct exploratory behaviour, impairment of differentiation inhibition, changes of emotional reactions. Behavioural changes were accompanied by shifts of cortisol, vasopressin, norepinephrine and adrenalin levels in blood of experimental animals. The maximal impairment of conditioned behaviour was observed 30 min after CRF microinjections and coincided with maximal activation of pituitary-adrenocortical system. On the basis of the data obtained we conclude that CRF-sensitive systems of the neostriatum participate in the mechanisms, underlying behavioural, vegetative and hormonal changes.