DECREASED MEASURES OF EXPERIMENTAL ANXIETY IN RATS BRED FOR HIGH ALCOHOL PREFERENCE

A prevalent notion holds that acute anti-anxiety actions of ethanol ar e important for the reinforcing properties of this drug, and might pre dispose individuals with pre-existing anxiety disorders for developing ethanol dependence. This notion remains controversial, and human stud ies have yielded conflicting results. Ethanol dependence is likely a h eterogenous disorder, and the discrepancies might be explained by a di fferent relationship between anxiety and alcohol reinforcement in diff erent subtypes of alcoholism. Recent results in experimental animals s uggest that antianxiety actions of ethanol are important reinforcers o f voluntary ethanol consumption in heterogeneous rats. Here, we examin ed whether the relationship is different in the AA line of rats bred f or high voluntary ethanol intake. Behavior was studied in two establis hed animal models of anxiety, a punished drinking conflict test, and t he elevated plus maze. in the conflict test, the AA line displayed a m arkedly disinhibited behavior over a range of shock intensities, compa red both with their counterpart, the ANA line, and with regular Wistar rats. On the plus maze, both AB and Wistar rats showed lower measures of experimental anxiety than ANA subjects. The phenotype of the anima ls was confirmed using a two-bottle free choice alcohol drinking proce dure. The disinhibited behavior and spontaneous ethanol preference of the AA line differs from what has been found in heterogeneous rats, an d displays similarities to genetically transmitted type II alcoholism according to the nomenclature of Cloninger.