receptor. In animal models, sigma-1 receptor antagonists decrease alcohol intake and reinforcement learning (Sabino et al., 2009a) and reduce excessive alcohol consumption in alcohol preferring rat selectively bred lines (Sabino et al., 2009b). Therefore, the sigma-1 receptor may perform a cellular function similar to nucleosome assembly proteins (NAP1) because both the sigma-1 receptor and NAP1 proteins play a key role in recruiting chromatin-remodeling complexes to regulate gene expression. Thus, one could hypothesize that genetic variation in NAP1L4 contributes generally to alterations in chromatin remodeling which could alter expression of neuropeptide genes (NPY) or dopamine-related genes (MAOB) affecting the binge-intoxication and/or withdrawal-negative affect addiction cycle domains.
