Effects of ethanol consumption by adult female rats on subsequent consumption by adolescents.

We used a two-bottle choice test to measure voluntary ethanol consumption by adolescent rats that had lived with ethanol-consuming or water-consuming adult conspecifics. We found that housing weanlings with either a virgin or a lactating adult female rat that ingested ethanol increased the weanlings' subsequent voluntary intake of ethanol when they were fluid-deprived and provided with choices between 8% ethanol solution and water for 2 h/day. Rats housed with both an ethanol-consuming virgin female and their water-consuming dam drank more ethanol than did rats housed with a dam and virgin female, both consuming water. Rats housed with an ethanol-consuming dam and ethanol consuming adult virgin did not drink more ethanol than did rats housed with an ethanol-consuming dam and a water-consuming virgin female. In sum: (1) young rats learned socially to consume ethanol. (2) Exposure to ethanol in mother's milk was not necessary for such social learning to occur, and (3) living with an ethanol-consuming unfamiliar, virgin female conspecific resulted in enhanced ethanol intake by adolescent rats, even if a water-consuming dam was also present.