Altered gene expression in a brain region affected by addiction may be linked to cocaine withdrawal, a National Institutes of Health-funded animal study has found.
Dopamine’s attachment to histones, proteins that wrap around DNA and help regulate genes, are altered by changes in gene expression. Dopamine is a neurotransmitter in the brain.
Dopamine contributes to cocaine addiction by acting as a chemical messenger, transmitting signals between nerve cells. Before this study, it was unknown how dopamine altered gene expression by modifying histones.
Researchers believed people recovering from cocaine addiction often relapse because the brains’ reward circuits have been rewired by prolonged drug use.
To discover the link, researchers blocked the fastening of dopamine to histones in subjects undergoing cocaine withdrawal. Results showed a lessening of cocaine-seeking behavior and a significant reversal of the gene activity changes.
This suggests altered gene activity has an impact on behaviors associated with drug craving. It also provides insight into the molecular basis for relapse and indicates new strategies for preventing it.
The study, published in Science, was supported by the National Institute on Drug Abuse, the National Institute of Mental Health, and the National Institute of Neurological Disorders and Stroke.