Infant rats respond differently to alcohol after nursing from an alcohol-intoxicated dam

Our previous studies indicate that rat pups are able to detect the low leve ls of ethanol (175 mg %) found in the milk of a moderately intoxicated dam. The present study tested the effect of infantile interactions (including s uckling) with ethanol-treated mothers on later behavioral responsiveness to ethanol's sensory properties. In Experiment 1, pups suckled from dams subj ected to a 2.5 g/kg ethanol dose (i.g.) or water-treated females during pos tnatal days (PDs) 3, 5, 7, 9, 11, and 13. During PD 15, these pups were exp osed to procedures to induce a conditioned aversion to the low level of eth anol (175 mg % in water), with lithium chloride as the unconditioned stimul us. Conditioning was more effective for pups with the prior ethanol experie nce within the nursing context. Greater responsiveness to ethanol in milk a lso was found for conditioning control pups that had interacted with intoxi cated dams than for those that had interacted with water-treated dams. Expe riment 2 determined that interaction with an intoxicated dam was sufficient for altered responsiveness to ethanol, in that the additional conditioning procedures of Experiment 1 were not needed for the effect. Generally, a re latively brief history of infantile interaction with ethanol-intoxicated da ms increased later responsiveness to ethanol's orosensory properties. The r esults suggest that moderately intoxicated dams within the nursing context provide information to the progeny that may lead to the establishment of et hanol-related memories. (C) 1999 Elsevier Science Inc. All rights reserved.