May 18, 2009

Molecular insights into cocaine addiction

U.S. researchers have found cocaine regulated molecular pathways that may lead to addiction treatments.

The study, published in Cell Press, finds long-lasting changes in behavior are elicited as cocaine regulates gene expression in a crucial reward region of the brain.

Although we have known for some time that changes in gene expression contribute to the long-lasting regulation of the brain's reward circuitry that is seen during drug addiction, how those specific genes are regulated is not well understood, senior study author Dr. Eric Nestler of New York City's Mount Sinai School of Medicine said in a statement.

Nestler and colleagues combined highly sensitive genetic isolation and screening techniques to study regulation of gene transcription in the brains of mice repeatedly receiving cocaine.

The researchers also found a previously unrecognized family of genes -- called the sirtuins -- involved in cocaine addiction. Chronic cocaine administration was linked with an increase in sirtuin gene transcription while increased sirtuin activity was associated the rewarding effects of cocaine being augmented, while pharmacological inhibition of sirtuins reduced the rewarding effects of cocaine and the motivation to self-administer the drug.