New research from the Mount Sinai School of Medicine in New York City sheds light on how cocaine regulates gene expression, specifically in the nucleus accumbens, a key brain reward region (Maze I et al. Proc Natl Acad Sci U S A. 2011;108:3035-3040). The findings indicate that cocaine use alters specific histone methylation markers, which normally silence the expression of regions of DNA.
Mice repeatedly exposed to cocaine expressed fewer of these markers than did controls. The effect persisted even after the mice had abstained from cocaine for 1 week. Some formerly silent DNA regions became active in the nucleus accumbens after cocaine use, likely reflecting global patterns of genomic destabilization in this brain region after repeated cocaine use, the researchers said.
Hampton T. Cocaine Gene Alteration. JAMA. 2011;305(13):1290. doi:10.1001/jama.2011.386