Opioids, like the commonly prescribed pain reliever oxycodone, are known for being highly addictive. In 2022, nearly 85,000 people died from an opioid overdose in the U.S.
, according to the Centers for Disease Control. Yet opioids are still being prescribed at alarming rates, particularly in Southern states, because of the lack of effective alternatives. Researchers at MUSC and around the country are studying the brain to understand more fully what makes these drugs so addictive in the hopes of finding better, nonaddictive medicines for pain relief.
Alexander Smith, Ph.D., now an assistant professor in the Department of Neuroscience at MUSC, made a discovery about how opioids function in the brain during his post-doctoral training in the lab of Paul Kenny, Ph.
D., at the Icahn School of Medicine at Mount Sinai. In a in the June 7 issue of , Smith and his team found that an understudied brain region responsible for aversion, the dorsal peduncular nucleus, is highly responsive to opioids.
Surprisingly, the in this brain region respond uniquely to opioids, contradicting the prevailing belief that opioids act primarily through dopamine in the brain. This discovery offers an exciting new area of research. "This is potentially a nondopaminergic mechanism for opioid reward, which is something people have been looking for a long time," said Smith.
The cells that release dopamine are normally set to an on position. But another cell, called an inhibitory neuron, keeps it from releasing .