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Biomedical subjects

N S Kurova

Publications and source records attributed to N S Kurova.

At least 19 recordsLinked to original sources
PubMed1984

[Shifts in spatial synchronization potentials of the rabbit cortex evoked by the administration of noradrenaline to the visual area].

Application of noradrenaline to the visual cortex of alert rabbits led to a general brief increase of the distant potential synchronization in the visual and motor areas as well as to a local rather steady (5-10 min) synchronization between the processes in the visual cortical area. Later a similar and even more obvious increase occurred between bioelectrical processes in the sensorimotor cortex. The synchronization increase seems to be favourable for excitation transmission.

Animals↗
PubMed1976

[The effect of low-frequency stimulation of the diencephalon on the topogram of cortical potentials in freely moving rabbits].

The spatio-temporal organization of the cortical potentials in rabbits was investigated by means of comparison of successive electroencephalotopograms. This systemic organization was characterized by the potentials' sagittal gradient and its inversion within the 4-6/sec range due to higher amplitudes in the frontal cortical areas, - during natural transition from the active to passive behavior as well as after low-frequency stimulation of the thalamic midline nuclei and of the hypothalamic supraoptic area. Single stimuli applied to the structures under study ordinarily prevented any obvious active behavioral periods, although entailed no long-lasting changes in the rest-activity dynamics.

Animals↗
PubMedDate not supplied

Influence of acetylcholine on shifts in spatial synchronization of cortical potentials of the rabbit, elicited by reversible interruption of the associations of the mammillary bodies.

A decrease in 25 out of 53 calculated coefficients of linear correlation of the potentials between pickups from the visual and motor areas of the cortex, far removed from one another, was observed during anode polarization (20-30 microA, 24 min) of the mammillary nuclei, the column of the fornix, and the mammillothalamic tract, using monopolar 24-channel pickup of the potentials of the cerebral cortex in six rabbits. Application of a 1-2% solution of acetylcholine to the visual area of the cortex leads to an increase in spatial synchronization (13 out of 53 coefficients of correlation) for 5 minutes and between the 10th and 15th minutes from the start of the application. With the combined effect of the polarization of these formations and of the acetylcholine applied to the cortex, reciprocal compensation of the changes in spatial synchronization which wer elicited by each of the influences separately was observed. The hypothesis is advanced of the existence of a nonspecific cholinergic synchronizing system which is active when the mammillothalamocortical connections are preserved.

Acetylcholine↗
PubMedDate not supplied

[Narrow-band changes in the the EEG spectral composition under the influence of an agonist and an antagonist of noradrenergic neuromediation].

At pharmaco-electroencephalographic examination of patients with neuroses narrow-band components was carried out of the EEG spectrum, which oppositively changed under the influence of sidnocarb and obsidan--agonist and antagonist of noradrenergic system, the initial hypothesis on the perspectivity of search of the EEG markers of the level of activation of the brain neurotransmitter systems thus being confirmed. Comparison of the obtained EEG-data with pharmacological properties of the applied drugs allows to project the aspects of further EEG studies of neurotransmission.

Alpha Rhythm↗
PubMedDate not supplied

[A comparative analysis of the change in the EEG spectral characteristics of rats during the activation and suppression of the catecholaminergic systems].

To find EEG-markers of catecholaminergic activation shifts EEG power spectra of white rats were computed before and after intraperitoneal injections of propranolol, metaproterenol, haloperidol, amantadine, or isotonic sodium chloride solution. Differential spectral characteristics were undergone to factor analysis and discriminant analysis. Factors with similar structure for both catecholaminergic systems were revealed in EEG-reactions to mutually antagonistic injections and relatively specific factors as well. The leading factor of adrenotropic injections described the augmentation of the spectral power in the range of 9-16 Hz induced by propranolol and its reduction by metaproternol. Similar factor was also revealed in reactions to dopaminotropic injections with the smaller value of discriminant function coefficient. One more common feature of EEG-reactions to catecholaminergic disturbances was found to consist of the reciprocal narrow-band shifts in the theta- and delta-diapasons. The leading factor for the recognition of dopaminotropic disturbances described the increase of EEG power in the band of 19-30 Hz at activation and its reduction at suppression of the transmitter system.

Animals↗
PubMedDate not supplied

[The effect of acetylcholine on shifts in the spatial synchronization of the cortical potentials in the rabbit evoked by the reversible interruption of the mammillary body connections].

To study the role of cholinergic transmitter system in the maintenance of sychronizing limbic influences, the dynamics of the spatial distribution of the changes of cross-correlation coefficients of rabbits EEG led by 24 electrodes, was estimated at application of acetylcholine solution to the visual cortical area in combination with anode polarization of mammillary bodies. Acetylcholine, which separate effect was connected with a restricted increase of the spatial synchronization of potentials, completely eliminated the effects of isolated polarization expressed in a significant decrease of a half of calculated correlation coefficients between EEGs of the visual and motor cortical areas. Nonspecific cholinergic synchronizing system is supposed to exist which is active under the conditions of the mammillo-thalamo-cortical connections being intact.

Acetylcholine↗
PubMedDate not supplied

[Shifts in spatial synchronization of rabbit cortical potentials evoked by applying acetylcholine and amizil to the visual area].

Acetylcholine solution application to the visual cortex of walking unrestrained rabbit led approximately in 5 minutes to a certain increase of the spatial synchronization of the cortical potentials at the small conditions, the the cortex, 24 EEG channels being used. Under the same conditions, the application of muscarinic antagonist amizil had an opposite more distinct effect. Endogenous cholinergic input increasing the spatial synchronization is supposed to play an important role in the formation of the spatiotemporal cortical potentials' organization necessary for the occurrence of complex behavioural acts.

Acetylcholine↗
PubMedDate not supplied

[Dynamics of the space-time organization of cortical potentials upon extinction of electro-defensive conditioned reflexes in rabbits].

Spatio-temporal distribution of cortical potentials formed by non-reinforced conditioned stimuli in 10 unrestrained rabbits, was studied in the course of extinction of a conditioned defense ear-shaking reaction to flickering light, by means of comparison of successive electroencephalotopograms. The first signs of the extinction were characterized by a periodical reversion of the momentary sagittal gradient of values of simultaneous cortical potentials, going on with the frequency of light stimulation (4 cps). Under these conditions, the probability of motor reaction to light was reduced. At a late stage of the extinction the potential gradient reversion had lower frequency characteristics for passive wakefulness and drowsiness of the rabbits.

Animals↗