Tolerance to the Ataxic Effect of Alcohol in Rats Selectively Bred for Saccharin Intake

Consumption of sweets correlates positively with alcohol consumption; alcoholic men prefer stronger sweet solutions than do nonalcoholic men and alcohol-preferring rats consume sweet solutions far beyond the limits of their normal fluid intake. Similarly, Occidental?s high saccharin-consuming rats (HiS) prefer alcohol more than do those selectively bred for low saccharin intake (LoS). Interestingly, however, LoS rats show stronger alcohol withdrawal than HiS rats. Withdrawal is often used as a proxy of alcohol tolerance?with severe withdrawal implying that tolerance to alcohol?s effects has developed?but measures of withdrawal do not directly index tolerance. Tolerance has not yet been studied in these rats. The present study examined tolerance directly in order to test the prediction that alcohol-experienced LoS rats would be more tolerant than HiS counterparts. Tests of ataxia, specifically the tilt-plane test, are frequently used as behavioral indexes of intoxication; thus, tolerance was tested using the tilt-plane, as well as the balance beam and horizontal ladder tests of coordination. Preliminary results (n=24) have yielded that HiS and LoS rats do not show significantly different levels of tolerance to a challenge dose of alcohol (1.5g/kg of 15% EtOH). Main effects of alcohol and saccharin on the tilt-plane apparatus could yield significant p-values with the addition of more rats