PRENATAL COCAINE ALTERS DOPAMINE TRANSPORTER BINDING IN POSTNATAL DAY-10 RAT STRIATUM

The effect of in utero cocaine exposure on the postnatal binding of th e radiolabeled dopamine (DA) uptake inhibitor [H-3]GBR 12935 to the DA uptake complex was examined in male rats. One set of pregnant Sprague -Dawley rats was given subcutaneous (s.c.) injections of cocaine (40 m g/kg) or 0.9% saline from gestational day (GD) 8-21. Another set of an imals received bilateral s.c. Silastic implants, each containing 60 mg cocaine base dissolved in polyethylene glycol (PEG) or PEG only, from GD 18-21. The density of [H-3]GBR 12935 binding to the DA transporter in striatum and mesencephalon was assessed by quantitative autoradiog raphy on postnatal day (PND) 1, 10, 30, and 60. Both treatment methods resulted in a decrease of [H-3]GBR 12935 binding in dorsal lateral st riatum of cocaine-exposed offspring on PND 10. There were no significa nt differences in [H-3]GBR 12935 binding between offspring of cocaine and vehicle-treated dams at any other time points examined. Thus, pren atal cocaine exposure by either daily injection from GD 8-21 or contin uous infusion from GD 18-21 resulted in a transient decrease in DA tra nsporter binding in the dorsal lateral striatum that was apparent on P ND 10. (C) 1996 Wiley-Liss, Inc.