Lack of response inhibition in rats prenatally exposed to alcohol.

Offspring of mothers who consumed either 32, 19, 8, or 0% of their daily caloric intake in the form of ethanol during pregnancy were tested for passive avoidance. At 18 days of age, the number of trials to criterion and the within-group variability were direct functions of the amount of ethanol consumed by the mother during pregnancy. At 41--53 days of age, alcohol-treated pups still required more trials to criterion than controls and had faster speeds into the shock compartment on the first trial. When the progeny of mothers consuming either 35, 17, or 0% ethanol-derived calories during pregnancy were compared for conditioned taste aversion to a lithium chloride solution, a linear dose-response function was again evident. Animals in the alcohol-treated groups showed less suppression of drinking than controls. These investigations indicated that the effects of alcohol exposure in utero were manifested in behavioral outcomes involving response inhibition that were not correlated with the more familiar physical symptoms.