Conditioning of aversion to alcohol orosensory cues in 5- and 10-day rats: subsequent reduction in alcohol ingestion.

Two experiments examined in 5- and 10-day-old rat pups the impact of alcohol olfactory aversions upon subsequent alcohol intake. In Experiment 1 it was observed that at both ages, animals given a single pairing of alcohol odor and LiCl subsequently consumed less alcohol than those in any of 4 control conditions (alcohol odor unpaired with LiCl, alcohol odor exposure, lemon odor paired with LiCl, and untreated animals). In Experiment 2, pups of both age groups were given LiCl following exposure to alcohol odor, the infusion of an alcohol solution or both stimuli simultaneously. Rats given explicitly unpaired presentations of the different conditioned stimuli and internal malaise served as controls. It was observed that equivalent aversions to alcohol ingestion were expressed whether the infants had experienced the alcohol odor, the alcohol infusion, or both, paired with toxicosis. These experiments extend the ontogenetic spectrum of circumstances in which olfactory experiences affect subsequent ethanol ingestion and also may indicate an early nondifferentiated processing of odorant and gustatory cues arising from an ethanol stimulus.