subunits examined. Furthermore, the mean expression levels for both the α2 and the α3 subunits were significantly correlated with the total amount of ethanol consumed (Floyd et al. 2004). In the same cohort of cynomolgus macaques, Hemby et al. (2006) found significant decreases in mRNA expression for: α2, α4, β1, β3, γ1, γ2, and γ3 in orbitofrontal cortex; β1, β2, γ1, and δ in dorsolateral prefrontal cortex; but no changes in anterior cingulate cortex. In addition, Anderson et al. (2007) showed that long-term ethanol self-administration reduces the sensitivity of amygdala GABAA receptors to the benzodiazepine flunitrazepam and decreases mRNA expression of β1 and γ2 subunits. Furthermore, there are significant effects of ethanol drinking on the γ2 subunit gene in males but not females; however, there was no correlation between subunit mRNA expression and total ethanol intake, suggesting that this gender adaptation is not related to drinking. Interestingly, GABAA receptor density, measured by [3H]Ro15–4513 binding, does not differ in the parietal and temporal cortex, cerebellum, or hippocampus after long-term ethanol self-administration in these cynomolgus macaques (Sullivan et al. 2005). Overall, the effects of ethanol in cynomolgus macaques differ from rat models in several aspects and suggest that studies in non-human primates
