Previous reports, in conjunction with the studies presented here, support a model whereby VTA Clock is important for negatively regulating reward and anxiety and NAc Npas2 is important for positively regulating reward and anxiety (Mukherjee et al., 2010; Coque et al., 2011; Ozburn et al., 2012; Sidor et al., 2015). This evidence concerns the gene NPAS2 and Anxiety.