Differences in sensitivity to the aversive effects of ethanol in low-alcohol drinking (UChA) and high-alcohol drinking (UChB) rats

A conditioned taste aversion paradigm was used to determine whether aversion to the pharmacological effects of ethanol, apart from orosensory cues, can contribute to differences in voluntary ethanol consumption in rats of the low-alcohol drinking (UChA) and the high-alcohol drinking (UChB) strains. "Alcohol-naive" UChA and UChB rats were injected intraperitoneally with ethanol (0.5, 1.0, 1.5, or 2.0 g/kg) or saline, paired with consumption of a banana-flavored solution during five conditioning trials. Repeated pairings of banana-flavored solution and ethanol at a dose of 1.5 g/kg produced aversion to the banana-flavored solution in UChA rats, but not in UChB rats, at comparable blood ethanol levels. In addition, the highest dose of ethanol tested (2.0 g/kg) produced stronger aversion to the banana-flavored solution in UChA rats, compared with findings in UChB rats. From these results it is suggested that rats of the UChA strain find the postingestional effects of high-dose ethanol more aversive than do UChB rats. Differences in voluntary ethanol consumption seem to be associated with differences in sensitivity to the aversive effects of ethanol. (C) 2001 Elsevier Science Inc. All rights reserved.