Several of the kinase activity-related genes (Table 2) identified as having altered expression levels in the CA group (Table 1) have been implicated in alcohol abuse. For instance, (a) Cav2 gene expression, which was reduced in the present study as was gene expression of the family member Cav, is increased in the ACB of iP rats after operant self-administration of ethanol (Rodd et al., 2008); (b) Dusp6 gene expression, which was increased in the CA group of the present study, is greater in iNP than iP rats (Kimpel et al., 2007), with gene expression differences also found between high and low alcohol-consuming mice (Kerns et al., 2005); and (c) Pkib gene expression is increased in the frontal cortex of alcoholics vs. nonalcoholics (Liu et al., 2006), which was elevated in the CA group of the present study as well. Interestingly, inhibition of PKA in the ACB shell increases ethanol intake (Misra and Pandey, 2006), and family member Pkia (cAMP-dependent, regulatory) gene expression is decreased in the frontal and motor cortices of alcoholics (Mayfield et al., 2002).
