Prenatal lorazepam administration is associated with GABAA receptor alterations in late embryonic and mature chicks

Prenatal benzodiazepine administration has been associated with alterations in behavior in young and mature animals. Prior studies of neurochemical changes in animals treated in utero have produced conflicting results. We used a chick embryo system to assess the effects of chronic lorazepam administration on binding and function at the GABAA receptor in late embryos and in mature animals. Administration of lorazepam for 10 days of embryonic development (E8-E18) led to decreases in binding of the chloride channel ligand TBPS and in muscimol-stimulated chloride uptake in late embryos (E18). Similar alterations were observed in mature animals after the same regimen of prenatal lorazepam. Persistent alterations in GABAA receptor binding and function after prenatal lorazepam may be due to effects of neuronal differentiation or on receptor regulation. These neurochemical effects may underlie the behavioral abnormalities associated with prenatal benzodiazepine administration.