Social Induction of Ethanol Consumption in Adolescent Rats, Rattus Norvegicus

Abstract

<p>Based on results of human and animal studies, it has been suggested that exposure to ethanol during early development leads to an increased likelihood of ethanol consumption by exposed individuals. Unfortunately, those results are sometimes conflicting and often incomparable due to subtantial differences in methodology. Additionally, it is difficult to determine whether there is a critical period or mechanism for the development of affinity for ethanol. In both human and animal studies, social exposure to ethanol has been confounded with other forms of exposure. In sum, no systematic evaluation of effects of exposure to ethanol during early development on subsequent ethanol affinity has been conducted to date.</p> <p>This thesis represents such a systematic evaluation, using a rodent model. In a series of seven experiments I assessed the relative and interactive effects of exposure to moderate doses of ethanol during three developmental stages (gestation, lactation and weaning) on subsequent voluntary ethanol consumption in adolescent Long-Evans rats. Results of experiments described in this thesis indicate: (1) Exposure to ethanol throughout gestation and lactation does not enhance voluntary ethanol consumption by adolescents unless such passive exposure is followed by opportunity to ingest ethanol during weaning. (2) Social exposure to an ethanol-consuming adult female during weaning is sufficient to enhance voluntary ethanol consumption by adolescent rates. (3) Neither direct access to ethanol during weaning nor access to ethanol in mother's milk is necessary for enhand ethanol consumption by adolescents after social exposure during weaning. (4) Any ethanol-consuming adult female can induce enhanced affinity for ethanol in adolescent rats, but weanling rats are more affected by cues from their dam than from another adult female when both are present. In summary, social exposure to an ethanol-consuming female during the weaning period is a sufficient condition for induction of ethanol consumption by adolescent rats.</p>