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L V Cherenkova

Publications and source records attributed to L V Cherenkova.

At least 19 recordsLinked to original sources
PubMed1983

Association brain systems and visually guided movements in the cat.

A study was made of contribution made by specific and association systems of the brain to the organization of visually guided movements in cats. Animals were trained to make two light spots coincide; one of them was guided by pressing the pedal. Ablation of specific visual areas of the neocortex did not affect the performance, whereas local lesions of association frontal and parietal areas caused severe deficits of visuomotor integration. Patterning of new programs compensated for the deficits. Destruction of the ventrolateral nucleus (VL) of the thalamus which is responsible for information transfer to association area brings about irrevocable impairment to the movements learned. Coagulation of ventral or dorsal portions of VL in trained cats specifically encroached the performance. In the former case, fast ballistic movements towards the target are affected, whereas in the latter tracking movements were disturbed. It is supposed that VL is a link between the two association systems, the interplay of which provides for activities of the mechanisms involved in sensory control of goal-directed movements.

Animals↗
PubMed1980

[Cortical biopotentials following intracortical injections of kainic acid].

The morphological analysis after intracortical injection of kainic acid revealed lesions of cell bodies and dendrites and intact afferents in the same cortical region. After the injection, the primary positive phase of cortical surface EPs during stimulation of the ventrolateral nucleus or contralateral forepaw disappeared whereas the negative phase remained though with a lesser amplitude, shortened latency, and not inverted in the deep cortical layers. The dendrite potential on the cortical stimulation was completely depressed in the poisoned cortical region. The initial positive phase seems to reflect the postsynaptic hyperpolarization of apical dendrites whereas the initial negative phase seems to consist of both pre- and postsynaptic components across the whole cortical diameter.

Animals↗
PubMed1980

Damages to cortical associative areas: effects on visual discrimination learning in cats.

Participation of the parietal and frontal cortical areas in pattern discrimination learning was studied in cats. Extirpation of the parietal cortex (fields 5 or 7) produced a deficit of visual discrimination of simultaneously presented patterns, but the animals were able to relearn the task. Postoperative learning of simultaneous discrimination was abolished, although successive discrimination of the same stimuli was still possible. The parietal associative areas probably participate in the organization of spatially and visually controlled movements. The frontal lobe ablation eliminated pattern but not brightness discrimination learning. The lesion of the frontal lobe is apparently connected with the occulomotor mechanism of pattern discrimination.

Animals↗
PubMed1978

Visual discrimination in cats: physical parameters of stimuli and effects of visual cortex ablation.

Correct reaction probability and minimum exposition time in visual form discrimination task were studied under the conditions of varying pattern parameters. The minimal exposition time depended on pattern contrast and pattern background ratio and on the number of screen position variations. However, it remained unchanged when the background luminance and pattern size varied within the suprathreshold range. The deficits of discrimination in the minimal exposition time conditions in animals with damages to the striate and parastriate cortical regions suggest that the visual cortex participates in the analysis of shortterm stimuli and is responsible for prolongation of the visual trace within the time necessary for object discrimination.

Animals↗
PubMedDate not supplied

The dependance of neuronal reactions of the sensorimotor cortex to a simultaneous complex stimulus upon the level of differentiation of its components.

The change in the neuronal activity of the sensorimotor area of the cerebral cortex of the cat was investigated in awake animals as a function of the level of differentiation of the components of a simultaneous heteromodal complex stimulus. Two groups of neurons in the sensorimotor cortex were distinguished on the basis of the character of this relationship and a number of other parameters. It was shown that the parameters of the reactions of all neurons recorded to the positive conditional stimulus following the consolidation of the conditioned motoric reaction are established first. Such parameters of the responses as degree of manifestation, intensity, duration, and the length of the latent period changed in the process of development. The reactions of neurons of both groups to inhibitory signals were stabilized only after the consolidation of the differentiation skill. In the process only the pattern of the discharge changed in the neurons of the first group, while in the neurons of the second group, the degree of manifestation of the response, its sign, duration, and length of the latent period could vary. Fluctuations in the level of differentiation following the development of the inhibitory conditioned reactions had an effect only on the responses of the neurons of the second group to the components of the complex.

Acoustic Stimulation↗
PubMedDate not supplied

[The characteristics of the neuronal reactions of the cat somatosensory cortex to a heteromodal complex conditioned signal].

On alert cats the change was studied of the activity of the neurones of the sensorimotor cortical area at instrumental reaction to a simultaneous heteromodal complex stimulus. It was shown that in the projection of distal limb areas a group could be singled out of neurones, which changed their activity in one direction depending on the character of presented signals. In these cells an increase of discharges frequency was observed in response to complex stimulus, consisting of light and sound signals. After the extinction of the motor reaction both to the complex stimulus and to its components neuronal reactions of lesser intensity was recorded, what determined the absence of the motor reaction. This group of neurones had receptive fields localized on distal limb areas, it was activated at fulfillment of the movement of catching the reinforcement and belonged to neurones of the pyramidal tract. The neurones with receptive fields on the whole limb surface or changing their activity at the animal pose change, had variable reactions to positive and differentiation stimuli.

Acoustic Stimulation↗
PubMedDate not supplied

[The dependence of the neuronal reactions of the sensorimotor cortex to a simultaneous complex stimulus on the level of the differentiation of its components].

On alert animals the change was studied of the neuronal activity of the sensorimotor cortical area of cats brain in dependence on the level of differentiation of the components of simultaneous heteromodal complex stimulus. According to the character of this dependence and a number of other parameters two groups of neurones were singled out in the sensorimotor cortex. It was shown that parameters of reactions of all recorded neurones of the sensorimotor cortex to the positive conditioned signal were the first established after consolidation of the animal conditioned motor activity. In the course of elaboration following parameters changed: expressiveness, intensity, duration and value of latency. Reactions of neurones of both groups to the inhibitory stimuli were stabilized only after consolidation of the habit of differentiation. Responses of the first group neurones changed only by the pattern of discharge, while the responses of the second group neurones could change by expressiveness of response, its sign, duration and value of latency. Oscillations of the differentiation level after finishing of the elaboration of inhibitory conditioned reactions affected only the responses of the second group neurones to complex components.

Acoustic Stimulation↗
PubMedDate not supplied

[Characteristics of the response of sensomotor cortex neurons of the cat during performance of rapid purposeful movements].

Neuronal activity of cat sensorimotor cortical area was studied during performance of movements of grasping a visual goal appearing for a short time. Characteristics and the pattern of neuronal discharge became stabilized in the process of animal training and did not depend on the time of goal presentation, absence or presence of the reinforcement under preservation of animal's motor reaction. Changes in responses were observed in situations of uncertainty: at 50% of reinforcement probability and (or) at successful performance of the motor reaction in half of cases.

Animals↗