Effects of prenatal ethanol exposure on heart rate, activity, and response suppression

Pregnant rats were intubated during days 10-14 of gestation with equal volumes of isocaloric ethanol-sucrose solutions. Groups 8g, 4g, and 0g received one-half these amounts of ethanol per kg body weight twice each treatment day. Although these maternal treatments did not significantly affect offspring birth weights, activity levels during classical conditioning were elevated in animals prenatally exposed to the 8g dose of ethanol. Further, the initial rate of extinction was slowed during CS presentations in a lick-suppression situation in this ethanol-exposed group. These findings are relevant to considerations of prenatal ethanol's effects on activity, reactivity, and the course of response extinction.