Dopamine signaling appears to be increased in the hippocampus, as indicated by large increases in tyrosine hydroxylase (Th) and VMAT2 (Slc18a2), both increased more than 4 fold, and the dopamine receptor subunit Drd2 (increased by 50%) (Table 2). These three genes are expressed at low levels. The upstream regulator analysis also suggests dopamine is more active in the alcohol-drinking animals (Supplemental Table 2). While the hippocampus is not thought to contain dopaminergic neurons, the VTA has dopaminergic projections to the hippocampus and these three mRNAs might be contained in the axons of these projections. These mRNAs were also detected in the hippocampus of human post-mortem brains in a comparison of alcoholics to controls (McClintick et al., 2013),
