PubMed Health⌕ Search

Biomedical subjects

V F Konovalov

Publications and source records attributed to V F Konovalov.

At least 19 recordsLinked to original sources
PubMed1994

[The electrical activity of symmetrical areas of the rat cerebral cortex during the use of a low-intensity UHF field].

Electrical asymmetry of electrograms of the rat symmetrical brain areas was decreased under the UHF irradiation of the animals. Non-modulated UHF field increased the 1.5 and 6 Hz rhythms in the left hemisphere, whereas modulated UHF field decreased the 1 Hz rhythm in the right hemisphere. The effects were only occurring at the initial period of the UHF fields use.

Animals↗
PubMed1990

Stability of resonance EEG reactions to flickering light in humans.

In order to study resonance phenomena in the EEG response to flickering light, 10 subjects were exposed to intermittent photic stimulation with the frequency of flashes linearly changing from 1 to 15 Hz and vice versa. Spectral analysis of occipital electrical activity revealed the occurrence of peaks of spectral density in those frequency components which coincide with the frequency of flashes. Such resonance peaks were observed at individually specific frequencies of stimulation. To assess the stability of the characteristics of the resonance phenomena, a repeated trial with 4-fold higher rate of changing the flash frequency was performed 3 months later. In a repeated trial the resonance phenomena were less pronounced, but were registered at the same frequencies as in the initial trial, showing significant test-retest reliability. The data obtained are interpreted in terms of provoking the activity of multiple brain oscillators having a narrow tuning to individually specific frequencies of photic stimulation by flickering light with the changing frequency of flashes.

Adult↗
PubMed1989

[The effect of stressfully loud sound on motor asymmetry in rats].

In 43 female Wistar rats, a loud sound did not alter the asymmetry in behavioral tests even if is was loud enough to induce seizure. Under apomorphine test, the sound tended to decelerate the rotation, the asymmetry being preserved both in sound-activated and in sound-resistant subgroups. A shortening of the rotation onset latency occurred in sound-activated subgroup which may be associated with an increased permeability of the hemato-encephalic barrier following the sound-induced seizure.

Acoustic Stimulation↗
PubMed1989

[Effects of lateralized electric stimulation of the brain on audiogenic convulsive attack in rats].

The influence of lateralized and bilateral electrical stimulations of the rat's brain on the course of audiogenic convulsive fit was analyzed. It was found, that after operative application of electrodes to the animal's skull the strength of fit and audiogenic seizure susceptibility decreased in all experimental groups. At the same time the second group, in which the left hemisphere was stimulated, essentially differed from other groups. The occasions of omission of some stages of fit were not so frequent, there, and only in this group after electrostimulation fits increased in the form of arising of new stages. This allows us to propose a special role of the left hemisphere of rats in forming a complete convulsive fit. The described observations resemble those of human asymmetry.

Acoustic Stimulation↗
PubMed1988

[Effect of intermittent photostimulation of varying frequency on the formation of trace processes and spectral components in the human EEG].

The EEG of occipital areas was recorded in adult healthy male subjects on presentation of haphazardly alternating intermittent light stimuli with frequencies varying from 15 to 5 Hz and from 15 to 25 Hz every 5 sec. Two groups were distinguished in respect to a greater or lesser domineering of the main frequency band of the range. Dynamic spectral analysis revealed obvious shifts of the EEG spectral composition in respect to the background under the effect of the stimulation, an enhancement of different bands of the range in light flickering, and the suppression of the EEG trace responses to the time in the EEG range coinciding in frequency with the frequency range of the photostimulation. The above changes were mainly characteristic of the 2nd group of subjects and mostly of the left hemisphere of the brain.

Adult↗