Chemical sensitivity of neurons of the sensomotor cerebral cortex at formation of defensive motivational excitation

Abstract

Purpose of the study. A purpose of the study was studying of features of inclusion of cortical neurons in defensive motivational excitation and a possible role of neurotransmitter factors of choline- and adrenergic nature in these processes.
Materials and methods. Experiments were made on 60 awake rabbits. According to coordinates of the stereotaxic atlas of Sawyer the electrodes were implanted in "the centers of avoiding" of a ventromedial hypothalamus. For registration of a single cortical neuron and microionphoretic introducing of chemicals into neuron a 3-channel microelectrode made of pyrex glass was used.
Results. Researches showed that microionophoretic applique of AcH directly in near neuronal space of the registered cells substantially changed the nature of reaction of cortical elements in response to motivational stimulation. Microionophoretic introducing of noradrenaline more than acetylcholine, caused potentiated reactions of inhibition registered in response to stimulation of "the centers of avoiding" of a hypothalamus while acetylcholine more than noradrenaline, promoted inversion of the initial sign of reactions of neurons towards increase in frequency of charges Conclusions. Neurons of a sensory-motor cerebral cortex of a rabbit are widely involved in processes of formation of the defensive motivational excitation caused by electric stimulation of "the centers of avoiding" of a hypothalamus. Microionophoretic introducing of acetylcholine and noradrenaline to separate neurons of a sensory-motor cerebral cortex essentially changes their sensitivity to electric irritation and "the centers of avoiding" of a hypothalamus that is shown in potentiation of inversion of the initial sign and pulse reactions of cells to motivational stimulation.