Sensitized effects of neuropeptide-Y on multiple ingestive behaviors in P rats following ethanol abstinence

Neuropeptide Y (NPY) suppresses ethanol drinking in alcohol-preferring (P) rats, an effect which is augmented following a single ethanol abstinence period. The present experiment tests both ethanol drinking and feeding in P rats following multiple abstinence periods. Female P rats had continuous access to 15% (v/v) ethanol and water for 6 weeks followed by 3 ethanol access cycles of 2 weeks with no ethanol and 2 weeks with ethanol. Following intracerebroventricular cannula implantation during the third period of ethanol abstinence, groups (n = 12-13/ dose) were infused with NPY (2.5, 5,0, 10.0 mu g) or aCSF prior to ethanol reinstatement. Two additional groups (n = 11 - 12/dose) were treated similarly except that ethanol access was uninterrupted, and they were infused with a single NPY dose (10.0 mu g) or aCSF. NPY increased food intake in all groups, and this effect was greater following ethanol abstinence. NPY suppressed ethanol intake, and this suppression lasted longer (24 h post-infusion) in rats with a history of ethanol abstinence periods than rats with a history of continuous ethanol access (4 h post-infusion). These results confirm past findings and indicate that global dysregulation of brain NPY systems during ethanol abstinence may render P rats more sensitive to the behavioral effects of NPY. (c) 2005 Elsevier Inc. All rights reserved.