In the study presented here, we stratified subjects based on their genotype at SNP rs279871 in GABRA2, which was previously shown to be associated with alcohol dependence (Edenberg et al., 2004). Given data pointing to a dose dependent allelic effect with SNPs in GABRA2 (Covault et al., 2004; Fehr et al., 2006), we hypothesized that drinkers homozygous for the high-risk allele would show a greater response to AO (as compared to a baseline of appetitive control odors; ApCO) than drinkers carrying only one copy of the risk allele. We focused our hypotheses on medial prefrontal cortex, where we had noted an association between family history and blood oxygenation level dependent (BOLD) contrast sensitive responses to these stimuli. We also examined other regions, post-hoc, including the VTA, ventral striatum, and caudate heads. In addition, we investigated how alcohol intoxication from intravenous alcohol administered during imaging interacted with GABRA2 genotype.
