Nursing experiences with an alcohol-intoxicated rat dam counteract appetitive conditioned responses toward alcohol

Background: Infant rats detect small amounts of alcohol (175 mg%) that are present in maternal milk whenever the dam is moderately intoxicated with al cohol. Interaction with an alcohol-intoxicated mother during the first 2 we eks of life facilitates the preweanling's subsequent discrimination of alco hol's orosensory attributes and produces conditioned aversion to alcohol. T he present study further analyzed the hedonic content of infantile alcohol memories established in the nursing context by testing the interaction betw een experiences with an alcohol-intoxicated dam and learning procedures aim ed at establishing an appetitive conditioned response toward alcohol. Methods: Experiment 1 was to determine appropriate parameters to establish a reliable conditioned preference for alcohol in 16-day-old infants. For co nditioning, intraorally infused sucrose solution (appetitive reinforcer) wa s paired with alcohol's orosensory cues derived from an acute state of alco hol intoxication (3 g/kg). Two control groups included an unpaired conditio n and a group given sucrose after water intubation. Infants then were evalu ated in an alcohol intake test. Relative to control animals, a reliable con ditioned preference for alcohol was registered in paired pups. In experimen t 2, these conditioning procedures were applied to infant rats which, befor e conditioning, suckled from darns subjected to a 2.5 g/kg alcohol dose (in tragastric) or from water-treated females during postpartum days 3, 5, 7, 9 , 11, and 13. Results: Experiment 2 showed that maternal treatment significantly affected the establishment of conditioned preferences for alcohol. Whereas pups rea red by control dams exhibited reliable appetitive conditioning to alcohol, infants raised by alcohol dams completely failed to develop appetitive cond itioning. Conclusions: The present results suggest that alcohol-related memories gene rated via infantile interactions with an intoxicated dam counteract subsequ ent conditioning of alcohol ingestion. In conjunction with prior studies, i t is concluded that alcohol-related nursing experiences are capable of prom oting alcohol memories with a negative hedonic content.