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 cocaine exposure significantly decreases basal extracellular concentrations of dopamine in the nucleus accumbens of young-adult offspring (4 weeks after cessation of cocaine treatment). Moreover, the increase in extracellular dopamine levels induced by a challenge dose of K+ (intracerebral 60 mM K+ artificial cerebrospinal fluid (aCSF) infusion) or cocaine (15 mg/kg i.p.) was significantly attenuated in rats exposed to cocaine during perinatal life with respect to controls. The alterations in mesolimbic dopamine transmission observed in these experiments might underlie behavioral abnormalities induced in rat offspring by maternal exposure to cocaine at dose levels which do not produce gross malformations and/or overt neurotoxic effects.