ANXIETY - A POTENTIAL PREDICTOR OF VULNERABILITY TO THE INITIATION OFETHANOL SELF-ADMINISTRATION IN RATS

Anxiolytic effects of ethanol have been proposed to be important facto rs in the initiation of ethanol consumption. To examine this hypothesi s, drug-naive Wistar rats were tested in the elevated plus-maze to det ermine their initial level of anxiety. Based on their response, we sep arated the animals into anxious and non-anxious groups. After that, an imals went through an oral ethanol self-administration procedure. Rats that were initially classified as anxious showed a significantly (P < 0.01) higher intake and preference for ethanol during the initiation phase of the voluntary drinking procedure than non-anxious animals. In another experiment, intraperitoneal (IP) injections of ethanol (0.5-1 .5 g/kg) produced dose-dependent anxiolytic effects in rats when teste d in the elevated plus-maze procedure. Blood ethanol levels following IP injections during the plus-maze test were similar to those reached during the oral ethanol self-administration procedure, which shows tha t the rats indeed drank sufficient amounts of ethanol to experience it s anxiolytic effects. These findings indicate that the basal level of anxiety plays an important role in vulnerability to alcohol drinking.