Putting the brakes on cocaine addiction

Researchers have discovered a brain mechanism that limits the rewarding sensations of cocaine. Recent research with rodents implicated histone deacetylases (HDACs), which are modulators of gene expression, in the regulation of cocaine-induced behaviors. However, the mechanism of this regualtion and whether it could modify addiction-related behaviors was unknown. Using a rodent model, the researchers discovered that cocaine triggered a novel signaling pathway that causes HDAC5 to move to the cell nucleus, where gene expression occurs. They found that this process limited the development of cocaine reward-associated behaviors. "Deficits in this process may contribute to the development of maladaptive behaviors associated with addiction following repeated drug use in humans and may help to explain why some people are more vulnerable to addiction than others," explains senior study author Dr. Christopher W. Cowan.