used in other studies where animals are subject to repeated periods of abstinence or discontinuous exposure to ethanol due to metabolism or voluntary drinking patterns. As a consequence, data from 72 hr exposure regimens provide a better understanding of what might be occurring to the EC system following a prolonged binge. The results from this work consistently show an increase in EC concentrations that is associated with reduced function of FAAH and CB1, but these effects reverse to basal levels after only 24 hr of withdrawal. In studies where the exposure is somewhat longer and the BEC oscillates because subjects are not under chronic pulmonary treatment, CB1 expression appears much more variable, and alterations to CB1 are brain region dependent (Gonzalez et al., 2002; Moranta et al., 2006; Pava et al., 2012). However, in long-term studies (over one month of ethanol exposure) where experiments are performed soon after the discontinuation of ethanol CB1 expression seems to be consistently reduced, and at least one study has reported elevated EC content (Mitrirattanakul et al., 2007; Ortiz et al., 2004). Interestingly, two studies that allowed subjects to go through a several week-long withdrawal prior to testing EC content or CB1 expression found elevated
