Prolonged chronic ethanol exposure alters neuropeptide Y and corticotropin-releasing factor levels in the brain of adult Wistar rats

► Two weeks of ethanol exposure produced no change in brain levels of NPY and CRF. ► Eight weeks of ethanol exposure produced significant effects on NPY and CRF levels. ► Changes in NPY expression during withdrawal from 8-week ethanol exposure are cyclical. ► A longer duration of ethanol exposure is necessary to alter levels of NPY and CRF.