Pain becomes chronic when the activity of first and second order neurons persists after damaged neuron heals or the tissue inflammation subsides. It's been known for years that for chronic pain to persist, a master switch must be turned on inside the peripheral neurons, though until now the identity of this switch remained a mystery.
Richard Ambron, Ph.D., professor of cell biology, and Ying-Ju Sung, Ph.D., assistant professor, both in the department of Anatomy and Cell Biology, have now discovered that the switch is an enzyme called protein kinase G (PKG). "We're very optimistic that this discovery and our continued research will ultimately lead to a novel approach to pain relief for the millions suffering from chronic pain," said Ambron.
The researchers found that upon injury or inflammation, the PKG is turned on and activated. Once activated, these molecules set off other processes that generate the pain messages. As long as the PKG remains on, the pain persists. Conversely, turning the PKG off relieves the pain, making PKG an excellent target for therapy. Ambron and Sung have applied for a patent for the pathway that turns on the PKG, as well as several molecules that inhibit it.
Based on the 2004 Americans Living with Pain Survey, 72 percent of people with chronic pain have lived with it for more than three years, including a third who have lived with pain for more than a decade. Yet nearly half of people with pain do not consult a physician for several months or longer, despite the impact the pain has on their lives.
MEDICA.de; Source: Columbia University Medical Center