Maternal barbiturate administration and offspring response to shock.

Gravid Sprague-Dawley-derived rats were injected SC twice daily with either 20 or 40 mg/kg pentobarbital sodium (PT), sodium phenobarbital (PH), or the same volume of the saline vehicle on days 9-21 of pregnancy. Pair-feeding was employed. Vital, developmental, and activity measures were obtained on the neonates and locomotor activity was measured from 3-10 months of age. Avoidance was measured sequentially in a shuttle box, and in an operant chamber beginning at 3 months of age. The PH-80 dams gained less weight over the gestational period, and PH-80 and PH-40 offspring had more neonatal deaths. These male offspring were hyperactive at maturity, and PH-80 rats were initially slower to escape experimenter-initiated shock. PT exposure caused transient neonatal and juvenile hyperactivity. PT rats performed more poorly on both the conditioned avoidance and Sidman shock schedules, and had significantly lower brain: body weight ratios at 1 year of age. All four drug groups outperformed the saline offspring on subject-initiated shock schedules (punishment). Sex of offspring was determined on postnatal day 4 and the sex ratio was shifted towards male births with both drugs relative to controls.