A fostering/crossfostering analysis of the effects of prenatal ethanol exposure in a liquid diet on offspring development and behavior in rats

Abstract

Pregnant Long-Evans rats were fed a liquid diet containing either 35% ethanol-derived calories (group E) or were pair-fed to group E dams using the same diet with an equivalent amount of sucrose-derived calories (group PFC) on days 7–18 of gestation. At birth half the litters were fostered to other dams of the same treatment and half were crossfostered to dams of the opposite treatment. Half the dams in each group had blood samples taken on their last day of treatment. Mean (±SE) serum ethanol concentration in group E was 167.1±22.6 mg/dl. Main effects of prenatal ethanol exposure were obtained on offspring body weight, olfactory orientation, figure-8 activity, straight channel swimming time, and gap-induced startle inhibition. Group E offspring weight differences were small (<7%) and transient (occurring between days 21–69). Group E offspring oriented less to their home cage scent, were more active in the figure-8 test, spent more time swimming the straight channel, and startled less than controls. Fostering was a significant main effect only on olfactory orientation and day 50–51 open-field. The tests of prime interest were interactions involving group and fostering. No such interactions were found. The data support the interpretation that postnatal maternal influences induced by prenatal treatment with ethanol in a liquid diet are not sufficiently strong modifying variables on offspring development or behavior to be a source of experimental concern.