Prenatal benzodiazepine administration. II. Lorazepam exposure is associated with decreases in [35S]TBPS binding but...

Prenatal benzodiazepine exposure has been associated with neurobehavioral alterations in humans and animals. To determine effects of prenatal benzodiazepine exposure on binding at the benzodiazepine and t-butylbicyclophosphorothionate (TBPS) sites on the GABAA receptor in mature offspring, we treated mice with lorazepam, 2 mg/kg/day, during days 13-20 of gestation. Binding was assessed at 6 weeks of age. There were no differences among controls, vehicle- or lorazepam-exposed mice in benzodiazepine receptor binding determined in vivo or in vitro. However, receptor density for [35S]TBPS binding sites was decreased in lorazepam-exposed offspring compared to the other groups. These data are consistent with prior neurochemical results indicating decreased TBPS binding and GABAA receptor function in several systems.