The proposed research is designed to investigate the effects of strain-dependent differences in maternal behavior on responses to ethanol with high and low levels of heritability. The central hypothesis is that maternal factors will influence ethanol responses but will have greater effects on responses with low heritability due to the larger influence of environment on those phenotypes. This research will examine maternal effects on ethanol responses in F, hybrids from reciprocal crosses of two inbred mouse strains with well-characterized differences in ethanol responses, C57BU6J (B6) and DBA/2J (D2). I will determine if F, hybrids reared by B6 dams and F, hybrids reared by D2 dams show differences in their responses to ethanol, thereby assessing the ability of maternal behavior to contribute to phenotype variation. Toward achievement of these aims, experiments will involve physiological and behavioral measurements. Ethanol responses with high levels of heritability that will be examined in B6, D2 and F, hybrid male and female offspring include locomotor responses to ethanol, ethanol drinking, and ethanol-induced conditioned taste aversion. Ethanol responses with low levels of heritability that will be investigated include hypothermic responses to ethanol and ethanol-induced conditioned place preference. Furthermore, I will investigate sex differences on ethanol responses in male and females B6, D2 and F, hybrid animals.