Head-dipping behaviors in rats exposed to alcohol prenatally as a function of age at testing.

While some studies suggest that the behavioral effects of prenatal alcohol exposure diminish as the animal matures, others are indicative of a persistent deficit. The present study further examined this issue using the rat as an animal model and exploratory behavior as the dependent measure. Using a pair-feeding procedure, pregnant Long-Evans rats were fed isocaloric liquid diets containing either 35% or 0% ethanol derived calories (EDC) during Days 6-20 of gestation. A third group received lab chow ad lib. At 25, 60, or 95 days of age, female offspring were tested in a hold-board apparatus mounted on a stabilimeter for a single 50 minute session. The results demonstrated that prenatal alcohol exposure facilitated exploration at all ages tested. The 35% EDC offspring dipped significantly more frequently and made more transitions between holes than controls. General activity levels did not differ between the 35% EDC and 0% EDC groups.