Conditioned taste aversion and the myers' high-ethanol-preferring rat

Abstract

Aims: Male and female Myers' high-ethanol-preferring (mHEP) rats were compared to outbred controls in a taste aversion paradigm. Methods: Alcohol-naïve rats were adapted to a 2-h access to water. Each rat was given either 0.05% saccharin (w/v) or 7% ethanol (v/v) as a novel solution for 1 h, after which either 0.5 M LiCl, as the aversive stimulus, or NaCl, as the control, was injected intraperitoneally. Each rat was tested 48 h later by presentation of the same solution. Results: After LiCl injections, saccharin consumption declined 21.6% in female Sprague-Dawley, 9.5% in female mHEP, 33.3% in male Wistar, and 38.3% in male mHEP rats. Ethanol consumption in these groups declined by 88.5, 30, 45 and 52%, respectively. These mHEP rats were then screened for 24-h alcohol consumption on a 10-day 3-30% ethanol vs water 'step-up' procedure. During the step-up procedure, only the male mHEP rats trained with ethanol for taste aversion drank less ethanol at the 3-5% concentrations than did rats trained with saccharin. The female mHEP rats did not learn an aversion to either saccharin or ethanol. Conclusions: The female mHEP rat consumes copious amounts of ethanol, but the basis for this consumption may be different from that of the male mHEP rats.