Expression of genes encoding the individual subunits of ionotropic GABAA receptor was assessed after acute and chronic intoxication of rats with ethanol. The chronic 1-month-long exposure to ethanol signifi cantly decreased (by 38%) expression of Gabrb1 gene in the hippocampus. Acute exposure to ethanol elevated expression of genes Gabrb1 (by 1.7 times), Gabra1 (by 3.8 times), and Gabra4 (by 6.5 times), although it diminished expression of Gabra2 gene by 1.4 times. In preliminarily alcoholized rats, acute intoxication with ethanol enhanced expression of genes Gabrb1 and Gabra5 by 1.7 and 8.7 times, respectively. There was neither acute nor chronic effect of ethanol on expression of gene Gabra3.

Four polymorphic GABRA2 gene variations: rs105733011, rs8168342, rs198286814, rs198837638 that can influence the formation of different biological effects of the organism when exposed to ethanol have been investigated. For rs105733011 polymorphism the frequency of occurrence of the CT genotype was found to be significantly higher (p < 0,05) among animals with «severe intoxication» – 37,0% than with «mild intoxication» – 14,0%. For rs198286814 polymorphism the tendency to the most frequent occurrence of the AG genotype in the group of animals with «severe intoxication» was established. Significant differences in the distribution of occurrence frequencies of the GG/AG genotypes in the studied groups for polymorphic loci rs8168342 and rs198837638 were not revealed. It was concluded that the rs105733011 polymorphism can be one of the genetic markers allowing to predict the degree of inhibitory action of ethanol in acute alcohol intoxication.