[Influence of the brain functional state evoked by spreading depression wave propagation on the recurrent waves properties].

EEG aftereffects of spreading depression waves were studied in waking rabbits in chronic experiments by spectral coherence analysis. Experiments were divided in two groups: early (from the first to the third-fourth experiments) and late (fifth-tenth experiments). During the early experimental series, unilateral persistent EEG changes consisting in an increase in the delta- and beta-band power with a simultaneous depression of the gamma-band activity were observed in the ipsilateral to SD hemisphere.

[Changes in the high-frequency electrical brain activity in the animal hypnosis state in rabbits].

The EEG spectral analysis applied to electrical brain activity of rabbits in the state of animal hypnosis revealed a 2-4-fold increase in the power of the sigma frequency band (12-17 Hz) and a 1.5-2-fold decrease in the gamma frequency (especially 40-70 Hz) in addition to well-known growth of delta (0.3-3 Hz) and reduction of theta activity (4-8 Hz).

Properties of spreading depression identified by EEG spectral analysis in conscious rabbits.

Reflection of cortical waves of spreading depression in changes in high-frequency gamma activity was shown to improve significantly in conditions of bipolar recording of brain electrical activity. Intense suppression of the EEG gamma range (37-47 Hz) was seen in all cortical areas studied at the moment of onset of waves of spreading depression. The drop in the power of EEG gamma activity had clear leading and trailing fronts, allowing the passage time of the wave to be evaluated in each cortical area, as well as the sequence of propagation.

[Spreading depression in a waking rabbit with the spectral EEG analysis].

It was shown that the manifestation of the SD phenomenon in dynamics of the cortical high-frequency gamma activity is rather prominent after bipolar interpretation of the common reference electrode derivations, i.e. when the modeling of the bipolar signal on the base of monopolar EEG recordings is used.

Suppression of EEG gamma activity--an informative measure of spreading depression waves in the neocortex of the conscious rabbit.

Spreading depression can arise spontaneously in convulsions, migraine attacks, vascular lesions, and other pathological brain states. However, the methodological complexity of recording a direct current potential in the neocortex in humans and conscious animals significantly limits studies of the functional consequences of spreading depression. The present report describes a detailed analysis of the EEG dynamics at the moment of development of spreading depression waves and identifies specific signs allowing spreading depression to be recorded without recording changes in the direct current potential.

[Suppression of gamma EEG activity as an index of a spreading depression wave in the neocortex of a waking rabbit].

A spreading depression (SD) can spontaneously develop in seizures, attacks of migraine, vascular disorders and other pathological states of the brain. However, problems in technique of recording the DC-potential in the neocortex of humans and waking animals substantially restrict the possibilities of studying functional consequences of the SD. In this article, the EEG pattern was studied in detail at the moment of the SD development.

[Intercentral reticulo-cortical relations of brain electrical activity during "animal hypnosis" in rabbits].

The electrical activity of the right and left sensorimotor and premotor cortical areas and right and left medulary reticular formation was recorded during "animal hypnosis" in rabbits. In this state, the spectral power of potentials (predominantly, in the delta-range) recorded from the left reticular formation was higher than that recorded from the right side. The value of the function of coherence between the right and left reticular recordings was decreased to 0.

[Interactions between electrical activities of the sensomotor cortex and the hippocampus during 'animal hypnosis' in rabbits].

The electrical activity of the left and right sensorimotor cortex and left and right dorsal hippocampus (CA3 fields) was recorded during "animal hypnosis" in rabbits. The "animal hypnosis" produced asymmetry in the spectral power of the hippocampal electrical activity due to an increase in the power of delta 1, delta 2, and theta 1 components in the left-hippocampus and decrease in the spectral power in the same ranges in the right-hippocampus. Hemispheric asymmetry in the electrical activity during the "animal hypnosis" was also expressed in the indices of coherence between the sensorimotor cortex and hippocampus.

[Interaction between two excitation foci in the central nervous system capable for summation].

The interaction between two dominant foci was carried out on different models of dominant. It was shown that the following pairs: latent motor and blinking excitation foci; hunger and hypnotic dominants, decaying polarization dominant (related with functioning of the left-hemisphere) and hypnotic dominant can function simultaneously. After repeated formation of a new dominant focus against the background of the existing stable dominant created earlier, a replacement of dominants takes place.

Coherence analysis of electrical activity in the rabbit brain during the process of substitution of dominants.

Coherence analysis was used to study intercenter relationships between biopotentials in the sensorimotor cortex (forelimb and blink representation areas) and the visual cortex in both hemispheres and the ventrolateral nucleus of the thalamus (VPL) of the left and right thalami during the formation of a motor defensive dominant (electrical stimulation of the limb skin) on a background of an induced (by stimulation of the cornea with an air jet) blink dominant. Characteristic electrophysiological measures of the dominant state (increases in the mean coherence level of potentials in the delta frequency range in structures involved in the functional defensive limb reflex system), along with the absence of behavioral manifestations of the motor dominant in the blink dominant, indicated that a cryptic potential dominant focus was created in the CNS in these conditions, and that this affected ongoing animal activity.

[A coherence analysis of the electrical activity of the rabbit brain during a shift in the dominants].

Coherence between the electrical activity in the sensorimotor (forelimb and blinking centers) and visual cortical areas, as well as VPL of the left and right thalamus was studied during creation of the motor defensive dominant by the serial electrical forelimb stimulation against the background of the blinking dominant (produced by the serial eye stimulation with an air stream). An increase in EEG coherence in the delta-range was observed in the structures which realized the defensive reflex. Formation of the latent defensive dominant destroyed the typical for the dominant state relationships of potentials in the cortical structures responsible for realization of the blinking reflex.

[An electrophysiological analysis of the process of a shift in a dominant].

Correlation of electrical activity of the sensorimotor (representation of the forelimb and blinking and visual areas of rabbit cerebral cortex and VPL of the thalamus was studied by the method of spectral analysis during creation of the motor defensive dominant (by serial electrical stimulation of the forelimb) at the background of the blinking dominant. In the structures which realize the defensive reflex (sensorimotor cortex and VPL of the thalamus) a typical for the dominant state increase in the spectral power was observed in the delta range. This electrophysiological phenomenon was not accompanied by behavioural manifestations of the dominant.

[The creation of a defensive dominant during the functioning of a blinking dominant in the rabbit].

Possibility of formation of motor defensive dominant (by serial electrical stimulation) at the background of active blinking dominant was studied in chronic behavioral experiments in rabbits. Formation of motor defensive dominant under such conditions was a problem. When the active dominant focus was inhibited and symmetrical representation of the other eye was activated formation of motor defensive dominant was also problematic.

[The restructuring of the intercentral relations of the electrical processes in the rabbit brain in a motor dominant].

On rabbits in chronic experiments by the method of coherent analysis were studied intercentral relations of biopotentials of the sensorimotor cortex and VPL of the thalamus at formation of the motor dominant created by serial electrical stimulation of a leg. In the structures connected with the motor function of the stimulated leg was revealed an increase of coherence of the potentials in the delta-range. At transition of the dominant focus to the inhibitory state and activation of the symmetrical centre of the other leg, in the centers constellation of this induced focus a reconstruction of the electrical processes took place being typical for the dominant.

[The intercentral relations of the biopotentials in the rabbit brain during the creation of a blinking dominant].

On rabbits in chronic experiment intercentral relations were studied of biopotentials of the sensorimotor cortical zone (blinking presentation in the cortex), VPM of the thalamus and motor nucleus of the oculomotor nerve at formation of blinking dominant created by serial stimulation of one eye by air jet. By the method of spectral-correlation analysis an increase was revealed of spectrum power and increase of COG of the potentials in delta-range in the structures connected with blinking function of the stimulated eye. At transition of the dominant focus to the inhibitory state and activation of the symmetrical centre of the other eye, in centers constellation of this induced focus a reconstruction of the electrical processes took place typical for the dominant.

Effects of various nitrates on pulmonary wedge pressure in acute myocardial infarction.

122 patients with acute myocardial infarction showing a positive antianginal response to nitroglycerin were examined. With the patients under continuous haemodynamic control including pulmonary artery catheterization the circulatory response to various nitrates administered orally, sublingually or transdermally was investigated. A safe time interval was determined for each drug to ensure stability of the attained wedge pressure reduction.

Localization of peptide hydrolysis in the enterocyte and the transport mechanisms of apical membrane.

1. The absence of the effect of anoxia on the hydrolysis rate of a number of dipeptides and one tripeptide by the intact and homogenized mucosa of the small intestine in different mammals (rat, mouse and guinea pig) has been demonstrated. 2.

[Effect of a dominant focus created in the center of the wink reflex on the local defense reflex in the rabbit].

The paper deals with conjugated inhibition of rabbit's defensive limb reflex at formation of a dominant focus in the center of the eye-lid reflex. In the initial period of dominant focus formation, when the dominant comes through the stage of summation reflex, electrocutaneous limb stimulation induced, along with successive summation, temporary inhibition of the forming dominant focus. The dominant focus formed in the eye-lid center did not induce conjugated inhibition of the limb defensive reflex.

[New data on the mechanisms of glucose transport in the small intestine based on an analysis of the role of serous-mucous flows].

The transport of glucose, other monosaccharides and disaccharides in the rat small intestine has been studied under the condition of a predominance of serosal-to-mucosal (SM) flows over mucosal-to-serosal (MS) ones. A dependence has been found of the efflux of glucose into the serosal solution on the duration of incubation, starting glucose concentration in the serosal solution, intestinal segment under study (proximal-distal gradient), action of glucose transport inhibitors (phlorizin, absence of Na+ in the incubation medium, anoxia) and temperature. In this paper, the hypothesis on entero-hematic circulation has been proposed, according to which recycling of glucose is one of the important manifestations of processes of microcirculation of substances between blood and the intestine.

[Action of levorin on glucose transport in the rat small intestine].

The technique of accumulating preparation of the mucosa and "turned out sac" was used to show that levorin, a polyenic antibiotic in a concentration of 10(-6) M, lowered the transport rate and accumulation of glucose by the epithelial cells of the rat thin intestine under conditions of oxygenation. Suppression of the glucose transport in the first stages resulted in partial inhibition of the transmembrane transfer. It is suggested that levorin suppression of the glucose transport through the erythrocyte apical membrane in the thin intestine is associated with a decrease in the electrochemical gradient of Na+.