HEALTH ISSUE: STATUS OF PAINKILLERS

A 'grimace scale' to help

find better painkillers

Paris: Scientists have for the first time created a sliding scale of pain for mice based on facial expressions, according to study published on Sunday."

       The so called "mouse grimace scale" will speed up the development of new analgesics for humans, and could help reduce unnecessary suffering of mice and other animals in biomedical research, the researchers said.

       "There are also serious implications for the improvement of veterinary care," said Jeffrey Mogil, a professor at McGill University in Montreal and the main architect of the study.

       Up to now, it was not known if degrees of discomfort and suffering in mice correspond to spontaneous facial responses, as is the case for people. Doctors and nurses routinely use such scales to assess pain in individuals unable to communicate verbally, such as infants and the cognitively impaired To fine out whether rodents grimace when it hurts, Mogil and colleagues recorded facial movements before and during the injection of a substance known to cause painful inflammation. The mice showed discomfort through facial expressions in a way similar to humans.

       When pain was more intense for example, the eyes narrowed, the bridge of the nose and cheeks bulged, the ears moved down and back, and the whiskers bunched up or flattened out against the face.