Don’t blow your brains out –
Oct. 28, 2020 – In the October 28, 2020 issue of the Journal of Neuroscience, researchers from the Medical University of South Carolina and the National Institutes of Health describe how reminders of drug use can change specific brain cells responsible for motivation, increasing the desire to seek drugs. Connections between these and other brain cells strengthen because the dendritic spines, the parts of the brain cells that receive messages from other neurons, enlarge in response to intercellular communication by molecules in the brain. This enhanced connectivity increases the urge to engage in drug use, making relapse more likely. Understanding this communication pathway could lead to more targeted treatments for drug addiction.
The study was led by MUSC Department of Neuroscience professor Peter W. Kalivas, Ph.D., and assistant professor Constanza Garcia-Keller, Ph.D., who works in the Kalivas lab.
For decades, the Kalivas laboratory has been studying the mechanisms behind drug addiction. In previous studies, Kalivas and his team have shown that an increase in the size of these spines correlates with how much an animal will work for a drug, such as cocaine. Interestingly, these spines enlarge in response to signals sent not from other neurons but from the extracellular matrix that surrounds these cells. They found that these signals from outside the brain cells lead to internal changes in the neurons to change their connections to other neurons.
“The key finding is that enlargement of spines is necessary and induced by cues that are associated with addictive drugs, not cues that are associated with natural rewards,” explained Kalivas.