PLACE CONDITIONING WITH ALCOHOL IN ALCOHOL-PREFERRING AND ALCOHOL-NONPREFERRING RATS

A place-conditioning procedure was used to examine the effect of selec tive breeding for ethanol preference on sensitivity to the rewarding a nd/or aversive effects of ethanol. On 4 alternate days, groups of seve n to eight alcohol-preferring (P) and alcohol-nonpreferring (NP) rats received IP injections of 0.0 (saline controls), 0.5, 1.0, or 1.5 g et hanol/kg body wt. immediately before 15-min confinement in a novel env ironment. On the 4 intervening days the same rats received saline inje ctions before 15 min confinement in a different environment. On day 9, a 15-min choice test was given with no injections, in which the rats could move freely between the ethanol and the saline-paired environmen ts. Dose-dependent avoidance of the ethanol-paired environment was obs erved in both lines of rats (1.0 and 1.5 g/kg), but the magnitude of t he avoidance was less in the P relative to the NP rats, indicating tha t ethanol was less aversive for the P rats. No evidence for a place pr eference was observed in either line with any of the ethanol doses. An innate reduced sensitivity to the aversive effects of ethanol in rats of the P line and/or an enhanced sensitivity to the aversive effects of ethanol in rats of the NP line may contribute to the different leve ls of oral ethanol self-administration observed in these selectively b red rat lines.