Abstract
Long-term consequences of early developmental exposure to drugs of abuse may have deleterious effects on the proliferative plasticity of the brain. The purpose of this study was to examine the long-term effects of prenatal exposure to cocaine, using the IV route of administration and doses that mimic the peak arterial levels of cocaine use in humans, on the proliferative cell types of the subventricular zones (SVZ) in the adult (180 days-old) rat brain. Employing immunocytochemistry, the expression of GFAP(+) (type B cells) and nestin(+)(GFAP(-)) (type C and A cells) staining was quantified in the subcallosal area of the SVZ. GFAP(+) expression was significantly different between the prenatal cocaine treated group and the vehicle (saline) control group. The prenatal cocaine treated group possessed significantly lower GFAP(+) expression relative to the vehicle control group, suggesting that prenatal cocaine exposure significantly reduced the expression of type B neural stem cells of the SVZ. In addition, there was a significant sex difference in nestin(+) expression with females showing approximately 8-13% higher nestin(+) expression compared to the males. More importantly, a significant prenatal treatment condition (prenatal cocaine, control) by sex interaction in nestin(+) expression was confirmed, indicating different effects of cocaine based on sex of the animal. Specifically, prenatal cocaine exposure eliminated the basal difference between the sexes. Collectively, the present findings suggest that prenatal exposure to cocaine, when delivered via a protocol designed to capture prominent features of recreational usage, can selectively alter the major proliferative cell types in the subcallosal area of the SVZ in an adult rat brain, and does so differently for males and females.