Ingenuity Pathway analysis revealed that many more categories were significantly altered by adolescent drinking in the Acb-sh than in the CeA (Table 4). The cAMP signaling pathways in both regions had a significant number of genes altered by adolescent drinking. In both regions, there were more genes up-regulated than down-regulated in the cAMP signaling pathways (7:2 ratio and 5:1 ratio in Acb-sh and CeA, respectively), suggesting ethanol exposure enhanced the activity of this pathway. However, there was only one gene (Dusp1) in common in the cAMP signaling pathway between the 2 regions, suggesting that the cellular mechanisms underlying the effects of ethanol are likely different in each region. It is noteworthy that Dusp1 also responds to glucocorticoids and is located in ethanol preference rat QTL Alc5. Paralleling the present results, another study from our laboratory revealed chronic ethanol drinking by adult P rats resulted in increased Dusp1 gene expression in the Acb-sh (McBride et al., 2010) but reduced gene expression in the ventral tegmental area (McBride et al., 2013).
