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Biomedical subjects

I V Chueva

Publications and source records attributed to I V Chueva.

At least 37 records · Page 2Linked to original sources
PubMed1994

[The neurophysiological correlates of the processes of decision making in the cerebral cortex during visual recognition in monkeys].

In behavioral experiments on monkeys tested for a delayed visual differentiation of different colours stimuli, neuronal pools were recorded simultaneously in the visual, prefrontal and inferotemporal cortex. Wrong motor responses were always followed by considerable readjustments of the unit activity patterns whereas in right decisions a synchronisation and a cross-correlation occurred between neuronal pools. Possible mechanisms of the decision making and the reasons for the desynchronisation in wrong responses, are discussed.

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PubMed1994

[The dynamic impulse activity of the neocortical neurons in monkeys with the task of visual recognition after short-term oxygen starvation].

During a 2.5-min. hypoxia in monkeys, a rearrangement of the unit activity occurred in the visual and prefrontal cortex. Following this, the motor response in delayed visual spatial reaction tack did not restore during several hours. The rearrangement involved appearing of sequential phases of hyperactivation and inhibition. Duration of the posthypoxic inhibition and ratio of posthypoxic hyperactivation frequencies to the background one were significantly greater in the prefrontal cortex than in the visual one.

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PubMed1993

[The participation of the cholinergic structures of the prefrontal and inferotemporal cortices in visual recognition processes in monkeys].

Characteristics of visual recognition were impaired by amysil influence in monkeys. This was accompanied by a considerable activation of unit activity in the prefrontal cortex. Amysil induced a considerable drop in the cross-correlation coefficients between simultaneous responses of neuronal populations in prefrontal and inferotemporal cortex.

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PubMed1993

[The effect of an antioxidant on the neuronal impulse activity of the prefrontal and inferotemporal cortices during visual recognition in monkeys].

The antioxidant oxymetacil improved cognitive characteristics and activated neuronal activity in the monkey prefrontal area in the process of delayed visual differentiation of different colour stimuli. It also considerably increased the mutual correlation coefficients between neuronal responses in prefrontal and inferotemporal cortex. The data obtained suggest a contribution of neuronal structures of these areas into the improvement of the cognitive characteristics.

Acoustic Stimulation↗
PubMed1992

[Visual recognition processes in monkeys and their neuronal correlates in the visual cortex: the effect of an M-cholinoreceptor blocker].

Unit activity was studied in the visual cortex prior to and after amyzyl administration in monkeys trained for delayed visual differentiation of different colour stimuli. The data obtained suggests that the cholinergic mechanisms of the visual cortex are involved in the visual recognition and seem to play different functional roles at different stages of the behaviour.

Acoustic Stimulation↗
PubMed1992

[An improvement in the cognitive characteristics of monkeys induced by an antioxidant: the neurophysiological correlates in the visual cortex].

Administration of oximetacyl considerably improved the cognitive characteristics of the processes of delayed visual recognition, increased auto- and cross-correlation coefficients in the responses of groups of neurons. The data obtained suggests nootropic properties of oximetacyl and participation of visual cortex of the monkey brain in realisation of these properties for improvement of the cognitive characteristics.

Acoustic Stimulation↗
PubMed1977

[Relationship between the responses of neurons in the cat lateral geniculate body and the contrast in the photic stimulus].

The responses of receptive fields of the cat lateral geniculate body to stimuli of different contrast were investigated. The neuronal responses increased linearly with the stimulus contrast when the contrast change with variation in the test stimulus intensity. This relation was nonlinear when background intensity was changed. The calculation of the number of impulses in different time intervals of the response (deltat) indicated that the dependence of this number on the contrast is the steeper, the larger deltat during the first 70-90 ms of the response. The Weber-Fechner law holds for the lateral geniculate body receptive fields.

Animals↗
PubMed1976

[Response of the receptive fields of the lateral geniculate body to temporal changes in the area of a light stimulus].

Neuronal responses of the cat LGB to light spots the area of which was changing in time with different speed, were studied. All the neurons responding to switching on and off of the test spot respond to changing in time of the spot area too. The on-neurons respond to enlargening of the area while the off-neurons - to its reducing. The on- and off-responses of these fields occurred at the moment of passing of the margin of reducing (growing) spot across a certain point of neuron's receptive field. This point changed when the speed of reducing (growing) of the test spot changed.

Animals↗
PubMed1975

[Image description at the level of the external geniculate body].

The responses of the receptive fields of the cat lateral geniculate body were investigated with a different position of the light stimuli in the receptive field. The stimuli were of the cross shape. On the basis of the obtained data the relief of excitation of the overlapping receptive fields was reconstructed. It is shown that at the level of the lateral geniculate body there exist a copy of the light stimuli. The description of the image is formed as a relief of excitation which changes in time. The magnitude of the excitation depends on the contrast of the stimuli.

Animals↗