The researchers have pinpointed a specific molecule in the brain as a possible target for treatment to prevent relapses, they revealed in an article published in the Journal of Neuroscience earlier this month.
Drugs are addictive because they “hijack” the brain’s reward system, which plays a role in making it pleasurable to eat and have sex, behaviours that are necessary for survival and reproduction.
The “hijacking” is extremely long-lived and often leads to relapses into abuse, especially when the individual is exposed to stimuli in the surroundings that are associated with the drug.
The team demonstrated that a receptor for the signal substance glutamate (mGluR5) in a part of the brain called the striatum plays a major role in relapses. The study examined what happens in individuals who lack the glutamate receptor. The experiments were performed on mice that were taught to ingest cocaine.
“Our findings show that the mice who lacked the receptor were less prone to relapse,” Linköping University associate professor of neurobiology David Engblom, who led the study, said in a statement.
“This is due to the fact that their reaction to reward had not been etched into their memories in the same ways as in normal mice,” he added. “The receptor seems to be a prerequisite for objects or environments that were previously associated with taking drugs, or something else rewarding, to create a craving.”
Engblom hopes that these findings and other studies on the mechanisms leading to drug addiction can result in courses of treatment tailored to what goes wrong in the brain of an addict.