In utero alcohol and postnatal methylphenidate: Locomotion and dopamine receptors

Prenatal alcohol exposure can cause central nervous system abnormalities an d dysfunction referred to as Alcohol-Related Neurodevelopmental Disorder (A RND). Repeated intermittent methylphenidate (Ritalin(R)) was used as a psyc hopharmacological challenge to reveal functional alterations in dopamine bi nding sites in rats exposed prenatally to alcohol. Pregnant Long-Evans dams were intubated with 0, 3, or 5 g/kg/day of alcohol from gestational day (G D) 8 to GD20. Adult offspring received repeated intraperitoneal injections of 0, 4, or 8 mg/kg of methylphenidate (MET), and were tested periodically for locomotor activity. Autoradiographic assessment of dopamine D-2 and D-2 receptors binding were visualized using [H-3]SCH 23390 and [H-3]raclopride , respectively, Prenatal alcohol did not produced significant dose-dependen t effects on adult locomotor activity. Repeated MET injections produced dos e-dependent sensitization of locomotor activity in all groups. The 3-g/kg p renatal alcohol group had a significantly decreased number of dopamine D-2 binding sites within the dorsal and ventral striatum. This effect was rever sed by MET. The neural changes detected in the lower alcohol group may indi cate persistent changes within the dopaminergic system due to prenatal alco hol exposure. (C) 1999 Elsevier Science Inc. All rights reserved.