Prenatal cocaine exposure decreases brain-derived neurotrophic factor proteins in the rat brain

The pregnant rats received daily sc injections of cocaine (30 mg/kg) or saline from the gestational day (GD) 7 to GD 20. At 1 week postnatal, all pups were killed and the hippocampus, cortex and striatum were dissected out. Levels of brain-derived neurotrophic factor (BDNF) under the basal condition and depolarization with high potassium (40 mM) were measured. The results showed that hippocampal BDNF levels under basal and depolarization conditions were all significantly lower in the pups prenatally exposed to cocaine than those exposed to saline. There were no significant differences in basal BDNF levels between the cocaine and saline groups in the cortex or striatum. However, the prenatally cocaine-treated pups showed significantly less BDNF release following high potassium depolarization than the saline-treated animals did in both these regions. The results support the suggestion that prenatal cocaine exposure decreases BDNF expression in the offspring.