corticosterone in rats (Spencer and McEwen 1990). This blunting of the HPA axis is associated with a reduction in corticotrophin releasing factor and adrenocorticotropin releasing hormone elevations following ethanol challenge (Lee et al. 2001). Furthermore, repeated ethanol withdrawal also leads to blunting of withdrawal-induced elevations in corticosterone levels (Borlikova et al. 2006). Thus, chronic ethanol administration induces adaptations of the HPA axis to promote loss of stress-induced increases in GABAergic neuroactive steroids that contribute to the regulation of homeostasis as well as ethanol sensitivity.
