Induction of Fos by alcohol self-administration was inspected by comparing immunohistochemical staining in brains of alcohol-naïve voles (A,C,E) to that of voles after two-hour access to alcohol (B,D,F) at 20X magnification. Very little induction was observed in the nucleus accumbens (A,B) or central nucleus of the amygdala (C,D), but there was apparent induction of Fos in the perioculomotor urocortin containing neurons (E,F). Arrows indicate examples of Fos positive nuclei.