Conditioned taste aversion and alcohol drinking: strain and gender differences

The present study examined the relationship between ethanol-induced conditioned taste aversion (CTA) and ethanol oral self-administration (OSA) in male and female rats (N = 183) from three related strains not genetically selected for their ethanol preference and differing in their emotional reactivity profile. The strains used were the Wistar Kyoto (WKY), Spontaneously Hypertensive (SHR) and Wistar Kyoto Hyperactive (WKHA). We hypothesized that differences between strains in sensitivity to the aversive properties of alcohol could explain the different propensities to drink alcohol solutions.

All animals were given three conditioning trials consisting of 20-minute access to saccharin solution followed by saline or ethanol injections (0.5, 1 or 1.5 g/kg, intraperitoneally). Animals subsequently had free access to ethanol OSA for 3 weeks, followed by two CTA trials.

Ethanol injections produce a dose-dependent reduction of saccharin consumption in all animals; moreover, the strength of the CTA is gender- and strain-dependent. Taste avoidance induced by ethanol injections disturbed the initiation of ethanol OSA in two strains (WKY and WKHA) but did not change subsequent long-term ethanol consumption in either strain. In addition, voluntary alcohol drinking experience does not attenuate ethanol-induced CTA, and no association was found between ethanol-induced CTA and ethanol OSA.

The data confirm the large variation among strains and between genders in alcohol drinking and taste-aversion learning, but suggest that there is no relationship between the sensitivity to the aversive properties of alcohol and alcohol drinking.