FIGURE 2.

Effects of ethanol on Gabra2 gene expression in stress- and reward-related brain regions of βE +/+ and βE –/– female mice. Gabra2 mRNA expression following binge-like consumption of either EtOH and water or water only in the DID paradigm. Two-way ANOVAs were used to examine the main and interaction effects of genotype (βE +/+, βE –/–) and treatment (EtOH drinker, water drinkers) in each brain region, results of which are depicted within each graph. (A) In the BNST, post hoc analysis indicated that, under basal conditions (water drinkers), βE –/– females have less Gabra2 expression, relative to βE +/+ females. Further, EtOH consumption reduced Gabra2 expression in βE +/+ females, but increased expression in βE –/– females, such that βE –/– females exhibited higher Gabra2 expression than βE +/+ females who engaged in binge-like EtOH consumption. (B) In the CeA, post hoc analysis indicated that, under basal conditions, βE –/– females have lower Gabra2 expression, relative to βE +/+ females. Similar to the BNST, EtOH also reduced Gabra2 expression in the CeA of βE +/+ females. (C) In the NAc, post hoc analysis indicated that, under basal conditions, βE –/– females have lower Gabra2 expression, relative to βE +/+ females. (D) In the VTA, post hoc analysis indicated that, under basal conditions, βE –/– females have lower Gabra2 expression, relative to βE +/+ females. Following EtOH consumption, βE +/+ females exhibited lower Gabra2 expression than EtOH-drinking βE –/– females due to an EtOH-induced reduction in Gabra2 in βE +/+ females. ^∗p < 0.05 compared with the water drinkers within the same genotype and ^#p < 0.05 compared with the βE +/+ genotype group that received the same treatment. Data are presented as means ± SEM; Bonferroni correction for multiple comparisons.