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Biomedical subjects

V I Gusel'nikov

Publications and source records attributed to V I Gusel'nikov.

At least 19 recordsLinked to original sources
PubMed1980

[Electrophysiologic analysis of the representation of the somatosensory system in the dogfish midbrain tectum].

Evoked responses in the dogfish tectum opticum were studied during electrical stimulation of the spinal cord, its dorsal roots and ramus ophthalmicus of the facial nerve. Recordings were obtained from different depth as well as from different points on the tectum surface. Evoked responses could be detected mainly on the contralateral side of the tectum opticum either as slow positive (spinal cord stimulation) or negative-positive (facial stimulation) waves which were preceeded by one or two fast, probably, presynaptic deflections and followed by a very slow low-amplitude negative wave. The evoked responses possessed the properties of tectal postsynaptic responses, being somatotopically distributed on the surface and reversely represented in the inner part of the tectal lamina. Projections of different inputs were widely overlapped, but specific areas of maximal activity were presented. These findings evidence that the tectum opticum performs a double function: a primary projecting and an integrative centre.

Animals↗
PubMed1978

[On--off impulse activity of carp retina amacrine cells].

Properties of spontaneous and light-evoked spikes of the "on--off" amacrine cells of the carp retina were studied. It was assumed that the dendrites of amacrine cells generated spike potentials and conducted them to the cell body. The data obtained suggest that the dendrites of amacrine cells have many spike-generation zones and that the transient depolarization component of the amacrine response to light is the compound spike consisting of many separate spikes generated in different parts of the dendritic arborization of cells. Possible functional role of dendritic spikes is discussed in respect to morphological properties of the "on--off" amacrine cells of the teleost fish retina.

Action Potentials↗
PubMed1977

[Postsynaptic excitation and inhibition in neurons of the general cortex of turtles during presentation of moving stimuli].

Reactions to moving stimuli were studied in the turtle general cortex. The evoked potentials, synaptic nature of their components and mechanism of their generation were analysed. The evoked potentials was negative-positive. The negative part consisted of fast negative complexes and a slow negative wave. These negative components reflected EPSP generated in the dendrites of the main cortex neurons. A rhythmical oscillation in the evoked potential started after the initial fast negative complex. The negative waves of this oscillation reflected EPSP and the positive waves, IPSP being generated also in the dendrites of the main cortex neurons. They had probably a recurrent generation mechanism. The positive wave of the evoked potential reflected dendritic IPSP in the main neurons.

Animals↗
PubMed1976

[Reactions and properties of the receptive fields of neurons in the visual projection zone of the pigeon hyperstriatum].

Impulse responses of neurons of the pigeon forebrain hyperstriatal part to stationary and moving visual stimuli were investigated. Particular attention was given to revealing a retinotopic projection in the region of visual representation in Wulst. It is shown that as the electrode moved gradually in the caudal direction in the region of visual projection of the hyperstriatum, the receptive fields of the neurons under observation displaced in the visual field in the opposite direction. The receptive fields of the ventral and dorsal hyperstriatum cells remain higher in the visual field and have larger diameters than the receptive fields of neurons of the accessory hyperstriatum. Neurons responses of the visual projection of the Wulst region depend on luminosity, size, speed and direction of the movement of the test-objects through the receptive field. The functional role of the retino-thalamo-telencephalic system in the visual integration in birds is discussed and a supposition is advanced on possibility to compare the Wulst region with striatal and frontal visual areas of the mammalian cortex.

Animals↗
PubMed1975

[Reactions of frog retinal rods to light].

The amplitude and shape of the rod photoresponses were investigated at different intensity, duration, wavelength and diameter of the light spot. Intracellular recordings were performed from the green and red rod outer sigments. An increase in the light intensity produced an increase in the amplitude and a decrease in the time rise of the response. An intensive light flash suppressed for a time the rod sensitivity to test flashes. At light spots of large diameter (100--1500 mum) delayed depolarizing deflection was observed. The latter was conditioned by illumination of receptor surroundings and, apparently, was due to horizontal cells activity. The possible role of the depolarizing effect of the rod surroundings illumination is discussed.

Animals↗
PubMed1975

[Intracellular on--off responses of carp retina amacrine cells adapted to the dark].

Dependence of the amplitude and latency of on and off responses of amacrine cells in the isolated dark-adapted carp retina upon the light spot intensity and diameter was studied by intracellular recordings. It is shown that the responses of amacrine cells to onset and offset of light consist of trasient depolarizations with oscillatory potentials and impulses. The latency of the on response decreases and the latency of the off response increases when the light spot intensity and diameter are increased. A dependence close to linearity on logarithm of the spot diameter up to 3 mm is observed for the on response amplitude with changes in intensity within 4 log. units. The amplitude and zone of summation of the off response decrease, when intensity of the stimulus is increased. It is supposed to result from differences in the amplitude and time characteristics to offset of light in the bipolars which give inputs to amacrine.

Animals↗