ENHANCED ETHANOL INTAKE IN PREWEANLING RATS FOLLOWING EXPOSURE TO ETHANOL IN A NURSING CONTEXT

Several studies have confirmed that diet selection patterns of adult r ats are at least partially established as a result of early experience s with food-related stimuli present in the milk of a lactating female (e.g., Capretta & Rawls, 1974; Galef & Clark, 1972; Galef & Henderson 1972). The present experiments were designed to investigate whether pr eweanling rats would similarly modify their acceptance of an ethanol s olution following exposure to this cue in a nursing context. In Experi ment 1, 8-, 12-, and 16-day-old rats were given ethanol, delivered int raorally in compound with milk, while given the opportunity to suckle an anesthetized dam. Subsequent testing revealed that 12- and 16-day-o ld subjects evidenced enhanced intake of the ethanol relative to contr ols, while 8-day-olds did not. Finally, the oldest (16 days of age) su bjects also expressed a conditioned aversion to the milk when tested 2 4 hr after conditioning and ethanol-ingestion testing. Experiment 2 de monstrated that the critical factor for ethanol conditioning was the o pportunity to suckle, rather than the simultaneous presence of milk. F inally, the aversion to milk observed in Experiment 1 was shown to hav e resulted from long-delay learning, due to the ingestion of a suffici ent dose of ethanol during testing to serve as an aversive uncondition ed stimulus (Exp. 3).