[Pathological changes in the central nervous system studied on the model of aluminum encephalopathy]. / Patologicheskie izmeneniia tsentral'noi nervnoi sistemy na modeli aliuminievoi éntsefalopatii.

Aluminum encephalopathy was formed in rabbits as a result of intraventricular administration of aluminum chloride. A study was made of changes in the neurological status, neuronal activity in the motor area of the cortex, electronystagmogram and neuronal structure in fields 4 and 17 of the cortex of large hemispheres. The animals demonstrated the worsening of olfaction, vision, audition, weakening of the reflexes of the craniocerebral nerves and motor reflexes. There was a decrease in spontaneous activity and irregularity of neuronal impulsation. Neurofibrillar degeneration in the neurons, vacuolization of the cytoplasm, swelling of the nucleus together with chromatolysis and ectopia of the nucleolus were recorded.

[Effect of fenamin and haloperidol on conditioned activity of neurons of the motor cortex and striopallidal system]. / Vliianie fenamina i galoperidola na uslovnuiu aktivnost' neironov dvigatel'noi kory i striopallidarnoi sistemy.

The activity of neurones in the motor cortex, caudate nucleus, putamen and globus pallidus was studied during elaboration of motor conditioned reflexes to time in rabbits, treated with 1-amphetamine and haloperidol. Mechanisms of reproduction of cells trace activity in the reflex to time at the omission of trials, reacted to 1-amphetamine by increasing the intensity of reactions in the motor cortex and inactivation in putamen cells. The curve of dynamics of intensity changes of trace discharges in the course of a series of trials omissions remained unaltered only in motor cortex; in the other structures it significantly differed from the norm of intact animals. Haloperidol depressed the mechanisms of reproduction of trace reactions of the globus pallidus cells, and made them almost fully inactive in the motor cortex; the putamen neurones reacted to haloperidol by an increase of trace reactions intensity. Against the background of the animal chronic 1-amphetamine intoxication, haloperidol normalized the dynamics and intensity of trace activity. "Therapeutic" effect of haloperidol was most distinctly expressed in the motor cortex and putamen cells, less--in the caudate nucleus and was completely absent in the globus pallidus.

[Interrelation between signal and reinforcing stimuli at the cellular level during extinction of motor conditioned reflexes]. / Vzaimosviaz' signal'nogo i podkrepliaiushchego stimulov na kletochnom urovne pri ugashenii dvigatel'nykh uslovnykh refleksov.

Comparative analysis of extinction of neuronal activation conditioned reactions in the motor cortex, the ventromedial and perifornical hypothalamic nuclei attest that the connection between the signal and reinforcing components of pairings in these structures of alert rabbits is more stable in defensive conditioned reflexes than in conditioned reflexes to time. A more stable connection between two components is established during conditioning in neurones of the motor cortex and the perifornical nucleus, and a less stable one at the level of the hypothalamic ventromedial nucleus and the medial geniculate body. In conditioned reflex to time a more stable connection has been detected in neurones of the motor cortex, the medial geniculate body and the perifornical nucleus, a less stable connection in the neurones of the hypothalamic ventromedial nucleus.

[Changes in the sign of the response of striopallidal neurons during elaboration of conditioned reflexes to time]. / Preobrazovanie znaka otveta neironov striopallidarnoi sistemy pri vyrabotke uslovnykh reaktsii na vremia.

During formation of motor conditioned reflexes to time (CRT) in alert rabbits, an increase in the number of neurones with activation and diminution of the number of cells with inhibitory trace activity was revealed when the stimuli were omitted, as compared with conditioned reactions (CR) to actual stimuli pairings, as well as a change in CR and CRT signs, as compared with the sign of cell responses to control tests. The changes were more pronounced in the caudate nucleus and the putamen. In the caudate nucleus and the globus pallidus, the number of cells capable of CRT in omissions of pairings increased as compared with the number of neurones which elaborate CR to actual pairings. Differences in the CR and CRT signs may suggest a difference in mechanisms of consolidation and reproduction of trace processes during elaboration of a motor behavioural act.

[Conditioned responses of striopallidal system neurons to time]. / Uslovnye reaktsii na vremia neironov striopallidarnoi sistemy.

The study was concerned with conditioned responses to time, elaborated in alert rabbits through pairing of sound stimuli with electro-cutaneous reinforcement, applied each 30 s. Conditioned responses to time were observed in 60% of neurones of the caudate nucleus, in 55% of neurones of the putamen and 59% of cells of the pale globe. Trace conditioned responses occured first in neurones of the putamen and of the pale globe and then of the caudate nucleus. No significant correlation between initial unit reactivity to the stimuli of paired modalities and their ability for elaboration of temporary connections was revealed. Conditioned responses to time were also found in 42-61% of the initially areactive units. Individual characteristics of formation and reproduction of trace activity in each of the studied brain structures are due to its structural-functional organization.

[Evolution of the functional properties of neurons during the process of elaborating a conditioned reflex]. / Evoliutsiia funktsional'nykh svoistv neironov v protsesse vyrabotki us lovnogo refleksa

A comparison was made between unit responses of the motor and auditory cortical zones and the parvocellular (auditory) and magnocellular nuclei of the medial geniculate body (MGB) to test presentations of sound and electro-cutaneous stimulation of the limb, both in units recorded before elaboration of conditioned connections and in those recorded in the course of defensive motor conditioning to sound. It has been found that in the course of conditioning, the functional properties of the neurones in the projection structures were changing towards an increase in the number of bimodal cells and a reduction of the number of monomodal cells which respond to a stimulus adequate for the given structure. The number of monomodal cells which in the tests reacted to a non-adequate stimulus became greater. Such changes were not manifested in the magnocellular part of MGB which plays the part of an associative nucleus in the subcortical auditory system.