Alcohol drinking patterns of young adult rats as a function of infantile aversive experiences with alcohol odor.

Recent studies have demonstrated that in the rat, alcohol intake patterns can be regulated by prior experiences with the odor of this drug. The efficacy of such regulation appeared to be limited to early postnatal stages of development. The present study supports the possibility, however, that early ethanol odor experiences are retained over considerable amounts of time and may play an effective role in the control of adult patterns of alcohol ingestion. Specifically, it was observed that rats exposed to pairings of ethanol odor and lithium chloride toxicosis (Etoh-LiCl group) during Postnatal Days 5, 10, 15, and 20 displayed as young adults (52-58 days) significant decreases in voluntary alcohol intake scores. This decrease was determined relative to control rats that had been safely exposed to ethanol odor (Etoh group) or given only lithium toxicosis but no ethanol odor (LiCl group) during Postnatal Days 5, 10, 15, and 20. Relative to these controls (Etoh and LiCl groups) the experimental subjects (Etoh-LiCl group) also exhibited significant decreases in their adult preference for ethanol odor, as assessed through an olfactory locational test. The present results indicate several ways in which conditioned aversion to ethanol intake may arise and imply that the transfer between olfactory and gustatory aversions takes place at the time of memory storage rather than at some later stage of memory processing. In a more general sense, the present results add to others in our series to support the notion that consideration of the effects of early experience with alcohol may aid in the clarification and control of voluntary alcohol intake patterns.