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Biomedical subjects

B Iu Mileĭkovskiĭ

Publications and source records attributed to B Iu Mileĭkovskiĭ.

At least 19 recordsLinked to original sources
PubMed2000

[Changes in the neuronal activity in the dorsolateral pontine region caused by electrical stimulation of the brainstem regions inhibiting movement and the muscle tone].

Activity of 44 mesencephalic locomotor area's (MLR) units and 38 pontine inhibitory area's (PIA) units was recorded during stimulation of the giganto-cellular reticular nucleus and oral pontine reticular nucleus inducing the hindlimb muscle tone inhibition in decerebrated rats. The muscle tone suppression was always accompanied by a decrease in the MLR and an increase in the PIA unit discharges. Stimulation of the brainstem inhibitory area seems to activate reticulospinal inhibitory system and suppress some MLR units relating to locomotion and muscle tone.

Animals↗
PubMed1999

[The inhibition of medullary reticulospinal neurons during the excitation of the dorsolateral portions of the pons blocking movement and muscle tonus in rats].

Hypothalamic stimulation increasing the muscle tone in hindlimbs, and excitation of the pontine dorsolateral areas inhibiting movements and the muscle tone in rats, were studied. Hypothalamic stimulation made 36.7% of the reticulospinal neurones to discharge in the form of short-latency spikes and to increase the muscle tone. The reticulospinal cells were completely inhibited by electrical stimulation of the pontine dorsolateral areas. 23.4% of the neurones only responded to the stimulation of the pontine dorsolateral areas. 35.9% of the cells did not respond to the stimulations at all. Excitation of the pontine inhibitory areas seems to prevent the descending activating effects from the brain rostral structures to spinal motor centres.

Animals↗
PubMed1997

[Neurophysiology and analysis of the phenomenon of catalepsy].

Neurophysiological mechanisms of the photogenic catalepsy (the "animal hypnosis"), genetic catalepsy, and cataplexy are discussed. The data obtained demonstrates a significance of the brainstem structures suppressing motor activity and the muscle tone in these conditions. Motor disorders associated with the general immobility are discussed from the standpoint of the evolutionary theory.

Adaptation, Physiological↗
PubMed1993

[The effect of the stimulation of sections of the pons that inhibit movement on the neuronal activity of the medial medulla oblongata].

Out of 249 units of the medial medullary area, 40 were ineffective, 25 fired antidromically, 48--orthodromically, 72 were inhibited and 64 developed a tonic firing pattern during stimulation of inhibitory pontine areas. The data obtained revealed that somatosensory neurons were mostly inhibited whereas reticulospinal neurons suppressed the activity of the hindlimb motoneurons.

Animals↗
PubMed1991

[The interaction of the thalamic parafascicular complex with the brain stem centers that inhibit locomotor activity].

Effects of electrical and chemical stimulation of the thalamus parafascicular complex on the rat behaviour and functional state of the inhibitory brain stem centres were studied in chronic experiments. The electrical stimulation of the parafascicular complex suppressed the locomotion and augmented multiunit activity in the inhibitory brain stem centres. The lesion of the raphe magnus nucleus and the medial portion of the reticular giganto-cellular nucleus eliminated the inhibition.

Animals↗
PubMed1990

[The effect of brain stem structures on the formation of defensive behavior in animals].

Electrical lesions of the nucleus cuneiformis, parabrachial medial nucleus, nucleus raphe median and the nucleus raphe magnus induce an active response of defence. Local microinjections of kainic acid in these sites result in a contrary effect. The findings suggest that inhibitory locomotor system of the brainstem may influence the formation of defensive behaviour in rats.

Aggression↗
PubMed1990

[The central neurophysiological mechanisms in the regulation of inhibition].

Electrical and local chemical stimulation of the n. cuneiformis, the parabrachial medial nucleus, the n. raphe median and the n. raphe magnus induces an inhibition of locomotor activity in rats. Changes of the legs' flexor and extensor muscles' tone followed electrical stimulation of the inhibitory zones. Lesion of the n. n. median and magnus raphe blocks the inhibitory effects of electrical stimulation of the n. cuneiformis and the parabrachial medial nucleus.

Animals↗
PubMed1988

[Neurochemical mechanisms of regulation in cataleptiform states in animals].

Influence of serotonin- and GABA-ergic systems on cataleptic responses to electrical stimulation of the medial parabrachial nucleus, cuneiform nucleus, median and magnus raphe nuclei, was investigated in chronic experiments on rats. The brainstem structures seem to form a morphofunctional inhibitory system participating in catalepsy.

Animals↗
PubMed1986

[Functional changes in the argentaffin cells of the stomach and electrical activity of the brain of the rat after injection of neurotensin into the hypothalamus and 3d ventricle of the brain].

Administration of neurotensin or its analogue into the hypothalamic structures altered the degree of activity synchronization among hypothalamic and brain-stem structures, the synchronization becoming most obvious among ventro-medial nucleus, amygdala and the central grey matter. Administration of the drugs into the 3rd ventricle and paraventricular nuclei suggested antagonistic effects of these peptides at the hypothalamic level. The data obtained could be regarded as local effects of the neuropeptides upon neurons of the paraventricular nucleus and as systemic effects upon argentaffin cells of the stomach antral portion.

Amygdala↗