Augmentation of Cocaine-Sensitized Dopamine Release in the Nucleus Accumbens of Adult Mice following Prenatal Cocaine Exposure

Behavioral changes in adult mice after prenatal exposure to cocaine have been identified. Mice exposed to cocaine in utero (40 or 20 mg/kg/day) and controls were given a sensitizing cocaine regimen (15 mg/kg every other day × 7 doses), withdrawn for 21 days, and challenged with 15 mg/kg cocaine. In vivo microdialysis for dopamine (DA), serotonin, and their metabolites in awake behaving mice on the first, seventh and challenge doses showed increased cocaine-stimulated DA release in the nucleus accumbens, which was significantly enhanced after prenatal cocaine exposure. This effect was not due to fetal malnutrition or changes in the total tissue DA content. Early developmental cocaine exposure may alter adaptation of brain reward systems to chronic psychostimulant exposure in adulthood.