SAN FRANCISCO — Chronic pain may be a symptom of addiction to natural opioids produced in the body, according to a study of mice.
Scientists caused inflammation in the paws of mice, allowed it to fade and then blocked the animals’ opioid receptors so the natural painkillers wouldn’t work. That led to withdrawal-like behaviors, as well as pain and the neural activity associated with pain, according to a report published in the journal Science.
It may be there’s a quiet battle between the internal painkillers and the pain pathways, said study author Brad Taylor, a pain pharmacologist at the University of Kentucky. As the body becomes dependent on its internal analgesics, the pain pathways become more sensitive. Exploring these pathways may explain why some people develop chronic pain.
