Substance Found in Rat Brains May Lead to New Painkiller

NEW YORK — Scientists have found a substance in rat brains that makes mice extra-sensitive to pain, a finding that paradoxically may lead to a new kind of painkiller for people.

The substance acts by binding to a “receptor” structure found in the brain and activating it, according to the researchers’ report in the Oct. 12 issue of the journal Nature. If a drug can be found that prevents that binding, it may be useful as an analgesic, researcher Jean-Claude Meunier said.

The pain-causing substance, which researchers propose calling nociceptin, also appears to be made in human brains.