Alcohol-mediated tactile conditioned aversions in infant rats: devaluation of conditioning through alcohol-sucrose associations.

Three experiments were conducted to assess the plasticity of ethanol-mediated conditioned aversions to a tactile stimulus in infant rats. Ten- and 11-day-old rats first acquired an aversion to a texture, by virtue of its pairing with alcohol-induced intoxication. This first conditioning phase was followed by an associative devaluation procedure, a second phase in which sucrose was intraorally infused during alcohol-induced intoxication. Pups were then tested for their texture preference. Results indicated that infant rats readily express conditioned aversion to a tactile cue as a result of tactile-alcohol pairings and that this associative learning was not state dependent. When alcohol-texture conditioning was followed by sucrose-alcohol pairings, the magnitude of the texture aversion was dramatically reduced (Experiments 1 and 2). In Experiment 3 citric acid rather than sucrose was paired with alcohol intoxication following texture-alcohol pairings. The results indicated that this procedure strengthened texture conditioned aversions in terms of increased resistance to extinction. Taken as a whole these studies indicate that infants rapidly acquire alcohol-mediated texture aversions and that this memory is malleable and can be reduced or potentiated through manipulation of the representation of alcohol's unconditioned properties.