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Biomedical subjects

B G Gafurov

Publications and source records attributed to B G Gafurov.

34 records · Page 2Linked to original sources
PubMed1988

[Primary dominant focus in thirst motivation].

In cats kept on the salt diet, spontaneous cortical EEG and electrohypothalamogram were recorded in stimulation of the tongue, stomach and intestine receptors with salt solutions. Longlasting bursts of hypersynchronized activity (HA) were recorded in the lateral and supraoptic nuclei of the hypothalamus, the bursts spreading over to the brain cortex in longer salt diets. The HA also were evoked with light and sound stimuli and disappeared after intracavital administration of water or after i.v. administration of saline. A primary focus of stationary excitation possessing some features of a dominanta in formation of the thirst motivation, seems to appear in the hypothalamus.

Animals↗
PubMed1986

[Pathogenesis of "diurnal" and "nocturnal" strokes].

A comprehensive clinico-physiological investigation involved 23 patients of whom 13 had had a "diurnal" and 10 a "nocturnal" cerebral stroke. The structure of the nocturnal sleep was studied by polygraphic recording; the authors also studied the circadian rhythm of the clotting properties of blood, pulse blood filling of the cerebral vessels and arterial pressure. It was found that the structure of dream in patients with a history of a "nocturnal" stroke was characterized by an increase in the activity of the mechanisms responsible for the phase of rapid sleep. Characteristic features of the circadian dynamics of the hemostatic system and hemodynamic parameters in patients with a history of a "diurnal" and "nocturnal" stroke were identified. A conclusion is drawn that the circadian distribution of acute disturbances of the cerebral blood circulation is determined by individual characteristics of some circadian rhythms of the patients' bodies.

Adult↗
PubMed1985

[Polygraphic features of the structure of nocturnal sleep in pathology of the left and right hemisphere in stroke patients].

The results of polygraphic examination of night sleep in 40 post-stroke patients are presented. In 22 of these patients, the focus was localized in the left, and in 18, in the right hemisphere. The pattern of sleep was found to vary with the hemispherical lateralization of the pathological process. Patients with damage to the left hemisphere and aphasia exhibited differences in the phase of rapid sleep and the time-course of the activation phenomena on the EEG during sleep related to the degree of speech disturbances. When the right hemisphere was impared, the most marked disturbances of the sleep pattern were elicited in patients with prominent manifestations of anosognosia. The data obtained are considered as features characteristic of the dysfunction of the cerebral nonspecific systems associated with hemispherical damage.

Aged↗
PubMed1983

[Electrophysiologic features of sleep and wakefulness in focal epilepsy with lateralization of the focus to the left and right cerebral hemispheres].

Forty-two epileptic patients with distinct localization of the focus in the left (22 patients) and the right (20 subjects) hemispheres of the brain were subjected to a combined electrophysiological examination including electroencephalography at rest and under intellectual exertion and also polygraphic recording of the night dream pattern. On the basis of the data obtained the authors analyze the function of the cerebral nonspecific activating and deactivating systems in relation to the localization of the focus. The differences detected are suggestive of the functional insufficiency of the activating mechanisms in the left lateral localization of the focus as compared with the right lateral one. The feasibility of utilizing the findings obtained in the differential management of epilepsy (with the lateralization of the epileptic focus taken into account) is discussed.

Adolescent↗
PubMed1975

[The structure of nocturnal sleep in stroke].

The paper deals with a polygraphic study of night sleep in 44 patients who had cerebral strokes with a different localization of the focus, in 10 patients with atherosclerosis and hypertensive disease (the control group). The structure of sleep following strokes was seriously imparied. Besides general traits, the changes were specific depending upon the focus of lesion. Differences were also displayed in patients with lesions of either the right or left hemisphere and their relationship with the opposition. The author stresses the importance of studying the interrelationship of sleep structure. It is assumed that disturbances in the sleep structure of the patients who have suffered from strokes are of importance in the rehabilitative period.

Adult↗
PubMedDate not supplied

The chemical nature of the hypothalamocortical activation underlying drinking behavior.

The injection of cholinergic substances (carbocholine, carbathin [karbatin], acetylcholine) into the lateral field of the hypothalamus of cats is accompanied by the appearance in the electrohypothalamogram of characteristic hypersynchronized activity and drinking behavior. The swallowing of water temporarily stops the hypersynchronized activity; the injection of adrenaline into the hypothalamus elicits the same effect. The injection of the same cholinergic preparations into the posterior sigmoid gyrus of the cerebral cortex is accompanied by similar, but less pronounced bioelectrical and behavioral effects. The presentation of a closed drink dispenser containing water to the animals against the background of cholinergic activation of the hypothalamus or cortex leads to desynchronization of the bioelectrical activity and suppression of the bursts of hypersynchronized activity. The drinking behavior of cats which appears on the basis of centrally created thirst motivation reflects the activity of a primary dominant focus in the hypothalamus and of a secondary dominant focus in the sensorimotor cortex. These foci are cholinergic in nature. The cessation of the drinking behavior may be related to the activation of adrenergic mechanisms of the same brain structures.

Acetylcholine↗
PubMedDate not supplied

The influence of stimulation of the hypothalamus on the choice of food during maintenance of rats on various salt and water diets.

Electrical stimulation of the lateral hypothalamus of rats maintained on a normal or salty diet with water deprivation leads to an increase in drinking excitability and to a decrease in the thresholds for salty food consumed. The stimulation promotes attenuation of the effects of the "mental" desalting of food that is achieved by a spatial co-placement of the nonsaltiness signal with salty reinforcement, and accelerates the conversion of the signal significance of the conditional stimuli associated with nonsalty and salty reinforcement as well. Electrical stimulation of the hypothalamus accelerates the formation of conditioned reflex aversion to salty food and the inhibition of conditioned reflexes in the direction of the corresponding food dispenser, and intensifies the existing state of thirst as well, imparting to it characteristics of a dominant motivation.

Animals↗
PubMedDate not supplied

Electrophysiological analysis of the conditioned reflex activity of cats during thirst.

The EEG of the cerebral cortex and the electrohypothalamogram (EHG) was recorded in cats with a salt load and water deprivation during the performance of runs conditioned to non-salty and salty food signals. The non-salty food signal against the background of thirst was accompanied only by the activation of the cerebral cortex, whereas the hypothalamus in addition to the cortex was involved in the activation in relation to the salty food signal. In those cases in which the non-salty signal was reinforced by salty food and the animal has eaten it (although it had rejected it in the presence of thirst), a strong activation of the cortex was observed, with involvement of the paraventricular divisions of the hypothalamus. The remodeling of the signal role of the conditional signals was achieved in accordance with the new quality of the food reinforcement. The hypothalamo-cortical mechanisms of the dominant motivation and its conditioned reflex effectuation are discussed.

Animals↗
PubMedDate not supplied

[The effect of hypothalamic stimulation on food choice with rats maintained on different water-salt rations].

Electrical stimulation of the lateral hypothalamus in rats induces an increase of water intake and decrease of thresholds of eaten salty food. These effects are displayed in control animals and under salt diet and water deprivation. The hypothalamus stimulation relaxes the effects of "psychic distillation" of food which occur during spatial coincidence of conditioned signal of insipid food with salty reinforcement. Besides, the trans-switching of signal significance of conditioned stimuli connected with insipid and salty reinforcements is accelerated. The electrostimulation of the hypothalamus accelerates the elaboration of conditioned aversion of salty food inhibition of conditioned runnings toward corresponding food-box, and intensifies the existent state of thirst transforming it in the dominant motivation.

Animals↗
PubMedDate not supplied

[Electrophysiologic analysis of the conditioned reflex activity of cats against a background of thirst].

EEG of the cerebral cortex and hypothalamic electrogram of cats during salt load and water deprivation were recorded at performance of conditioned running elicited by signals of insipid and salt food. The signal of insipid food presented during thirst was accompanied only by the cerebral cortex activation, while the salt signal involved in activation not only the cortex but the hypothalamus as well. In cases when the insipid signal was reinforced by salt food and the animal ate it (though during thirst it rejected the food), strong cortex activation was observed with the involvement of paraventricular parts of the hypothalamus. During intense thirst reversal was obtained of the signal role of the conditioned cue in accordance with the new quality of the alimentary reinforcement. Hypothalamo-cortical mechanisms of dominant motivation and its conditioned provision are discussed.

Animals↗
PubMedDate not supplied

[The participation of the posterolateral area of the hypothalamus in rats in the conditioned-reflex choice of food with different rations].

A week salt load and partial water deprivation of rats lead to disturbance of conditioned activity: decrease of adequate runs to the feeder with salted food and disinhibition of differentiations. In cases of shift of insipid signal to the feeder with salted food the animal ate alimentary reinforcement of such a degree of salinity which was rejected by the animal at realization of run in response to the salt signal. Against the background of thirst a trans-switching of signal role of the conditioned signals was performed in accordance with the new quality of the alimentary reinforcement (the feeders changed their places). The role is discussed of the external and internal signalization in regulation of gustatory thresholds and participation of the lateral hypothalamus in these mechanisms.

Acoustic Stimulation↗