expression in the periaqueductal grey, hypothalamus, and ventral tegmental area (Pava et al., 2012). Importantly, cannabinoid-induced catalepsy was not altered by ethanol pre-treatment suggesting the modulation of CB1 function by ethanol is region or at least circuit specific. Together the studies on cross-tolerance between ethanol and cannabinoids indicate that pre-treatment with ethanol or THC can significantly alter the response to subsequent doses of the other compound, and the more recent studies implicate alterations in the EC system as central to this effect.
