SENSITIVITY OF RAT BRAIN SENSORIMOTOR CORTEX NEURONS TO MEDIATORS IN HEMORRHAGIC STROKE

Abstract

The problem of post-stress disorders of cerebral circulation, the most severe of which is cerebral hemorrhage, or hemorrhagic stroke, is extremely urgent. Concerning the survival rate, previous studies have shown that in the same type of conflict situations, individuals resistant and predisposed to emotional stressful influences are clearly distinguished. However, the neural mechanisms providing neuromediatory regulation of responses to stressful effects are still little studied. The analysis of neurochemical sensitivity to acetylcholine and norepinephrine of the sensorimotor cortex neurons of rats having different activity according to behavior parameters, i.e., resistance to emotional stress influences before and after experimental hemorrhagic stroke (EHS) was carried out. The recovery process after an EHS due to neural activity in prognostically stable (VA) and predisposed (NA) to stressful situation rats has individual characteristics. Acute stress influence before EHS development changes the nature of neurons activity of the sensorimotor cortex in VA and NA rats on the third and seventh day after EHS. EHS leads to specific changes in the sensitivity of neurons to acetylcholine and norepinephrine in VA and NA rats. Acetylcholine microionophoresis causes activation of the neuron impulse activity in VA and NA rats, and these changes are the same after EHS. Acute stress influence before EHS development does not change nature of neuron responses to norepinephrine microionophoresis in VA animals. On the contrary, in NA rats loss of neuron sensitivity to norepinephrine during EHS development against stress was noted. It is possible that acute stress influence before EHS development can change brain noradrenergic system activity in NA rats, which are prognostically predisposed to stress influences. The data obtained stress the plasticity of the central nervous structure in development of response to stressful influences. (The ethics commission approval protocol number is 18-15 from 13th of Marth 2018.)