The effects of cocaine on corticogenesis in the developing murine brain were examined at the University of Louvain Medical School, Brussels, Belgium, and the Massachusetts General Hospital, Boston, MA. Two groups of 5 pregnant mice were injected with 20-40 mg/kg/day of cocaine hydrochloride from the 8th day of gestation until term. Examination of brains of embryos from embryonic day 15-18, post-natal pups from birth to 10 days, and adults showed disturbances of corticogenesis and brain growth and reductions in the number of live pups per litter. Neocortical architecture was disrupted and various steps of gliogenesis were altered. Interference with neurogenesis in the germinative zone could be attributed to cocaine-induced recurrent ischemia and inhibition of DNA synthesis. 
COMMENT. An estimated 10-15% of pregnant mothers deliver infants who have been exposed to cocaine in utero. Some develop behavioral impairments and structural brain abnormalities at birth (Kosofsky BE. NIDA research monograph 1991). In a separate series of experiments the same authors injected rat pups ages 8, 15 and 28 days and adult rats with cocaine 30 mg/kg. As early as 8 days, a 5-6 fold induction of striatal mRNA was evident before cortical-immediate early gene-induction was demonstrable. Cocaine induced alterations in gene transcription during critical developmental periods may alter CNS form and function and may relate to the gestational timing of the cocaine exposure.