Mice 'feel pain' just like humans

laboratory mice grimace when they feel pain much like humans, according to a controversial study into measuring painful discomfort in animals, published in the journal Nature Methods.

The researchers subjected mice to moderately painful stimuli and found that they could estimate the level of pain the animals felt by monitoring facial expressions such as closing the eyes, flattening the whiskers against the face or puffing out the nose and cheeks. Professor Jeffrey Mogil of McGill University and the University of British Columbia in Canada, said that the resulting "mouse grimace scale" was similar to the way humans express pain and could be used to assess how much discomfort animals feel during vital medical experiments aimed at alleviating pain.

"The mouse grimace scale provides a measurement system that will both accelerate the development of new analgesics for humans, but also eliminate unnecessary suffering of laboratory mice in biomedical research. There are also serious implications for the improvement of veterinary care more generally," Professor Mogil said.