The same region on rat chromosome 4 also includes the candidate gene Npy (Neuropeptide Y; Spence et al., 2005). Numerous studies in animal models have shown that NPY plays a role in alcohol preference and consummatory behavior (Badia-Elder et al., 2001; Badia-Elder et al., 2003; Badia-Elder et al., 2007; Caberlotto et al., 2001; Cowen et al., 2004; Ehlers et al., 1998; Kimpel et al., 2007; Pandey et al., 2003; Schroeder et al., 2003; Spence et al., 2005; Tecott and Heberlein, 1998; Thiele and Badia-Elder, 2003; Thiele et al., 2004a; Thorsell, 2007). For example, infusion of NPY reduces ethanol intake in P rats (Gilpin et al., 2003), and Npy-deficient mice consume more alcohol than wild-type mice (Thiele et al., 1998). It has also been shown that cocaine administered in Sprague-Dawley rats reduced Npy mRNA in the prefrontal cortex, and reduced NPY-like (NPY-LI) immunoreactivity in the cingulated cortex and nucleus accumbens (Wahlestedt et al., 1991). In the same rat strain NPY-LI immunoreactivity was found to be expressed in the dentate gyrus, a region of the hippocampus where this expression is not typically
