[Investigation of the anti-motion sickness effect of 3-hydroxypyridine derivatives].

Experiments with rats showed that three out of 12 3-hydroxypyridine derivatives (ethyl-methyl hyd- roxypyrine succinate, SK-132 and IBCP-2 - had an anti-motion sickness effect stronger than of scopolamine, the reference vestiboloprotector. The anti-motion sickness effect of ethyl-methyl hydroxypyrine was also demonstrated in experiments with cats. Apparent anti-motion sickness effect of ethyl-methyl hydroxypyrine (mexydol) was found in 69% of healthy male volunteers which is comparable with the effect of scopolamine (62%). In experiments with immobilized cats (myorelaxation drugs) the microelectrode technique and microontoiphoresis of physiologically active substances revealed that ethylmethyl hydroxypyrine influences the majority of neurons in the medial vestibular nucleus (61%). Suppression of cell spontaneous activities in more than one half of cases can be stopped completely or attenuated significantly by bicucculine, a specific GABA(A)-receptor antagonist. In 42% of neurons ethyl-methyl hydroxypyrine subdues the response to vestibular stimulation which is likely to underlie the anti-motion sickness effect.

Neural correlates of the results-of-action acceptor in a functional biotechnical complex.

This report presents data illustrating the neurophysiological features of efferent-afferent convergence on cortical neurons. During combination of stimulus of pyramidal tract axons with electrocutaneous reinforcement, some of the study neurons were found to change the parameters of their activity evoked by stimulation of this tract: evoked responses started to reproduce the structure of responses to the reinforcement. The most dynamic rearrangements of pyramidal tract responses were obtained in experiments in which the study neurons were included in a biotechnical complex with feedback, the complex consisting of "neuron-computer-stimulator-animal" and actually being an analog of a natural functional system. The role of efferent-afferent convergence on CNS neurons in the development of the results-of-action acceptor of a functional system for a voluntary behavioral act is discussed.

[Neuron correlates of the action result acceptor in a functional biotechnical complex structure]. / Neironnye korreliaty aktseptora rezul'tatov deistviia v sostave funktsional'nogo biotekhnicheskogo kompleksa.

This study presents data illustrating neurophysiological features of the efferent-afferent convergence on the cortex neurons. It was established that, during the process of combining stimulation of the pyramidal tract (PT) axons with electrical skin reinforcement, a significant amount of neurons under study changed parameters of the activity evoked by the PT-stimulation. The most clear reconstruction of the PT-responses was obtained in experiments with inclusion of neurons into biotechnical complex by means of the feed back: "neuron-computer-stimulating devices-animal", representing an analogue of the functional system. The role of afferent-efferent convergence of the CNS neurons is discussed in dynamic deployment of the action result acceptor in the functional system of natural behavioural act.

[Effect of nootropic agents on impulse activity of cerebral cortex neurons]. / Vliianie nootropov na impul'snuiu aktivnost' neironov kory bol'shogo mozga.

The effect of nootropes (semax, mexidol, and GVS-111) on the activity of individual neurons in various cerebral cortex regions was studied by microelectrode and microionophoresis techniques in cats immobilized by myorelaxants. It was established that the inhibiting effect of mexidol upon neurons in more than half of cases is prevented or significantly decreased by the GABA antagonists bicuculline and picrotoxin. The inhibiting effect of semax and GVS-111 upon neurons in more than half of cases is related to stimulation of the M-choline and NMDA receptors, respectively.

[Movement disorders in the context of P.K. Anokhin's theory of functional systems]. / Bolezn' dvizheniia s pozitsii teorii funktsional'nykh sistem P.K. Anokhina.

The authors' own findings and the data available in the literature as to movement diseases (MD) in animals and man were reviewed in the context of P. K. Anokhin's theory of functional systems. The functional system of the human body's gravity center is detailed. There is evidence for that disintegration processes underlying MD first occur in the mnestic sphere since due to genetic and/or ontogenetic causes, memory has no preserved no motor programme required to achieve the end net efficiency of performance of this functional system,--to maintain the definite position of the gravity center of the body and its related vegetative status upon stress-induced vestibular exposures. Based on the above concepts of the pathogenesis of MD, its preventive measures have been proposed and tested, which include drug (nootropic agents) and non-drug (a special complex of physical exercises for children aged 2 to 7 years, which will form permanent motor programs in memory in definite periods of their ontogenesis) measures.

[Efferent-afferent convergence as a structural-functional basis for a mechanism of an acceptor of action results]. / Efferentno-afferentnaia konvergentsiia kak strukturno-funktsional'naia osnova apparata aktseptora rezul'tatov deistviia.

In investigation data illustrating neurophysiological features efferent-afferent convergence in CNS are presented. Possibility of involvement of the efferent-afferent convergence mechanism in development of the acceptor of action results apparatus is considered. The role of parietal associative cortex as the integrative zone and zone of interaction the collateral pyramidal excitations with the nature afferent excitations is also discussed. The functional role of efferent-afferent convergence and interaction within the cyclic outline: motor cortex-parietal associative cortex-caudate nucleus-pallidum-thalamus-frontal cortex-motor cortex is analysed.

[The spontaneous and evoked neuronal activity of the parietal associative cortex in cats during motion sickness]. / Spontannaia i vyzvannaia aktivnost' neironov temennoi assotsiativnoi kory u koshek v protsesse ukachivaniia.

In the experiments with the cats a spontaneous and induced activity of the neurons (57) of parietal associated cortex during motion sickness was studied. It was found that after a 15 min motion sickness 54 percent of the examined neurons displayed suppression, 20 percent of neurons did an increase of spontaneous activity. Twenty-six percent of neurons did not respond to motion sickness. The dynamics of induced neuronal responses under motion sickness effect was complex, a direction of the changes in induced responses frequently did not agree with that of alterations in a spontaneous cellular activity. The more stable changes of induced responses have been in the neurons with phase responses to the fight and electrocutaneous stimulation. After 45-min effect of motion sickness, the light-stimulated responses were characterized by an increase of early and suppression of late components of a response, and the responses to electrocutaneous stimulation displayed mainly a suppression of the early components of the responses.