Researchers isolate target for therapies to treat cocaine addiction "The critical role of the AMPA receptor in cocaine addiction is clear," said Dr. Ghazaleh Sadri-Vakili.
BOSTON, Oct. 29 (UPI) -- A new study by researchers at Massachusetts General Hospital suggests a newly identified neural target is key in contributing to cocaine cravings following a period of abstinence.
A litany of genes and neural receptors have been implicated in the science of addiction. But in studying the behaviors of lab mice, scientists found that by simply by manipulating a receptor protein that influences cravings -- a protein known as the AMPA receptor -- they could diminish the likelihood of a drug relapse.
"The critical role of the AMPA receptor in cocaine addiction is clear," Dr. Ghazaleh Sadri-Vakili, director of the NeuroEpigenetics Laboratory at Mass General and senior author of the new study, explained in a press release. "We have known that activation of the AMPA receptor in the nucleus accumbens -- an area of the brain important for drug addiction -- promotes the resumption of cocaine seeking in animal models, and this study identifies an increased contribution of calcium-permeable AMPA receptors to this process."
In their research, scientists at Mass General the University of Pennsylvania found chronic cocaine use changed the makeup of AMPA receptors in the rodents' brains. As part of the study, mice were given cocaine for 21 days, then were withheld from the drug for 10 days. After their cocaine binge, the mice were found to have less of a particular component that controls the receptors calcium-permeability.
In isolating one of the major neural components in the processes of addiction, self control and relapse, researcher were also able to finger a route to reversing the damage down to the augmented receptors.
After the ten days of abstinence, researchers gave half the mice an enzyme, called ADAR2, that replenished the component of the receptors that had previously been diminished by cocaine use. As a result of the increased presence of the enzyme, the receptor was normalize and the mice were less likely to relapse than those without the enzyme therapy.
The findings were detailed in a study published this week in the journal Molecular Psychiatry.