On the Horizon: A New Way to Treat Pain

By Jane Farrell

Researchers have identified two molecules that perpetuate chronic pain, and that may pave the way for more effective, less addictive medicines.

A study from the Johns Hopkins University and the University of Maryland said that the molecules may play a role in the phenomenon that causes uninjured areas of the body to be more sensitive to pain if they are near an area that has been injured.

The findings were published in the journal Neuron.

"With the identification of these molecules, we have some additional targets that we can try to block to decrease chronic pain," says Xinzhong Dong, Ph.D., associate professor of neuroscience at the Johns Hopkins University School of Medicine and an early career scientist at Howard Hughes Medical Institute. "We found that persistent pain doesn't always originate in the brain, as some had believed, which is important information for designing less addictive drugs to fight it."

For the study, the investigators looked at the trigeminal nerve, a system of pain-sensing nerves within the faces of mice. When the researchers pinched certain regions of that system, they found that adjacent areas were more vulnerable to pain, even though they themslves hadn't been pinched. In humans, according to a news release from Johns Hopkins, an example of a similar phenomenon would be a hand throbbing even though only the thumb had been injured by a hammer blow.

An estimated 116 million Americans are affected by chronic pain that persists for weeks, months or years after an injury or condition is treated. According to Johns Hopkins, chronic pain costs $600 billion in medical interventions and lost productivity. It can be caused by everything from nerve injuries and osteoarthritis to cancer and stress.