MATERNAL COCAINE EXPOSURE ALTERS MESOLIMBIC DOPAMINERGIC FUNCTION IN RAT OFFSPRING

Hooded Lister female rats were treated with either saline or cocaine ( 20 mg/kg s.c.) from gestational day 10 every other day until weaning ( postnatal day 25). In vivo microdialysis has shown that maternal cocai ne exposure significantly decreases basal extracellular concentrations of dopamine in the nucleus accumbens of young-adult offspring (4 week s after cessation of cocaine treatment). Moreover, the increase in ext racellular dopamine levels induced by a challenge dose of K+ (intracer ebral 60 mM K+ artificial cerebrospinal fluid (aCSF) infusion) or coca ine (15 mg/kg i.p.) was significantly attenuated in rats exposed to co caine during perinatal life with respect to controls. The alterations in mesolimbic dopamine transmission observed in these experiments migh t underlie behavioral abnormalities induced in rat off spline by mater nal exposure to cocaine at dose levels which do not produce gross malf ormations and/or overt neurotoxic effects. (C) 1998 Elsevier Science B .V.