Prenatal and postnatal exposure to diazepam: effects on opioid receptor binding in rat brain cortex.

The effects of chronic perinatal or postnatal administrations of diazepam on opiate receptor development in cerebral cortex and striatum were studied at two different post-treatment ages, using tritiated ethylketocyclazocine, the prototypic kappa-opiate, for measurements of opiate binding site ontogeny. Prenatal plus postnatal exposure to diazepam markedly decreased the total number of binding sites for [3H]ethylketocyclazocine in the rat cerebral cortex and striatum at 14 days of age. Postnatal diazepam treatment alone did not alter [3H]ethylketocyclazocine binding site development in cortex or striatum. These results suggest that development of opiate receptors in rat brain can be altered by prenatal exposure to diazepam.