fifteen brain regions examined, including cingulate cortex, hippocampus, dorsal striatum, NAc, BLA, and cerebellum. In this study, rats were treated with ethanol (7.2%) via a liquid diet for 15 days prior to tissue collection, but the BECs obtained by these animals were not reported. Therefore, the discrepancy between these results and others may be due to methodological differences resulting in lower or more variable BECs than those obtained in other labs. Additionally, a subsequent study using the same treatment regimen for 10 days found that CB1 was reduced in the striatum and substantia nigra after 3 hrs of abstinence from ethanol when withdrawal symptoms were present (Rubio et al., 2008). These results indicate that this treatment paradigm produces alterations in CB1 expression that are highly dependent on the duration of abstinence. Regardless, the large majority of data suggest that ethanol treatments associated with the development of tolerance and dependence produce an initial down-regulation of CB1 expression that is followed by an up-regulation as acute withdrawal symptoms subside.
