Researchers working on mice have found an enzyme in the brain that appears to make pain last after nerve injury and they hope to use it as a new target to treat chronic pain in people.

In their paper, published online in Science, the scientists in Canada and South Korea said they managed to alleviate pain after blocking the enzyme, protein kinase M zeta.

"It provides us with basic understanding of the brain mechanism for chronic pain," lead author Dr. Min Zhuo, a physiology professor at the University of Toronto, wrote in an email.

"It not only provides a new possibility to design new pain medicine, but it also helps us to understand why many drugs fail to control chronic pain."

Dr. Zhuo and colleagues found elevated levels of protein kinase M zeta in the anterior cingulate cortex of the brains of injured mice.

To confirm the enzyme's function, they knocked out a gene in another group of mice which they believed was responsible for triggering the production of the enzyme.

They subsequently found that those mice experienced less or no chronic pain after nerve injury.

The research team hopes its work will help in the design of a new class of drugs that blocks this enzyme.

Science. Posted December 3, 2010.

Tan Ee Lyn • Reuters Health Information © 2010