Excessive ethanol drinking following a history of dependence: Animal modelof allostasis

Alcohol withdrawal symptoms, particularly negative emotional states, can pe rsist for months following the removal of alcohol. These protracted withdra wal symptoms have been implicated as an important trigger of relapse to exc essive drinking in alcoholics and may represent a long lasting shift in aff ective tone as a result of chronic alcohol exposure. It was shown previousl y that ethanol-dependent rats increased their operant responding for ethano l when tested during the first 12 hr after withdrawal. The purpose of the p resent experiments was to determine the persistence of this finding by exam ining operant oral ethanol self-administration in rats with a history of ph ysical dependence upon ethanol, detoxified and then allowed a two week peri od of protracted abstinence. The results of these experiments indicate that operant responding for ethanol was enhanced during protracted abstinence b y 30-100% and remained elevated for 4-8 weeks post acute withdrawal. These results have important implications for understanding the characteristics a nd mechanisms underlying vulnerability to relapse. (C) 2000 American Colleg e of Neuropsychopharmacology. Published by Elsevier Science Inc.