of PP-1 and protein kinase A (Svenningsson, Nairn, & Greengard 2005). DARPP-32 has been implicated in maintenance of morphine-induced CPP (Narita et al. 2010) and suggested as a putative therapeutic target for opiate addiction (Mahajan et al. 2009). ATPIF1, a mitochondrial ATPase inhibitor, plays important and diffuse roles in energy regulation. Although the degree to which gene expression data from peripheral blood monocytes correlates with that of brain remains unclear, altered expression of PHACTR4, and perhaps ATPIF1, deserves consideration as an alternative route through which our findings could be explained.
