Mice Make Grimaces When Experiencing Pain

Most research laboratories around the world rely on various animals to conduct their experiments on. House mice are undoubtedly the most popular choice for a wide array of investigations, and, as such, the small rodents can indeed be credited as our unsung heroes. The dark side of research is that, most of the times, the procedures these unsuspecting creatures need to undergo tend to involve them getting hurt in one way or the other. A new investigation shows that, when in pain, mice can grimace in very much the same way we do, Nature News reports.

In our case, we basically grimace to show that we are not comfortable with something. This is most obvious when we experience pain. Our faces get all distorted, and everyone with a little empathy can understand that we are in pain. Apparently, the same holds true in lab mice as well. When faced with painful stimuli, they too distort their faces, depending on the intensity of the pain they are experiencing. This suggests a gradual mechanism of experiencing such stimuli, the research team behind the new investigation says.

“This is the first study that has examined facial expressions of pain in non-human animals,” explains human pain psychologist Kenneth Craig. The expert, who is based at the University of British Columbia (UBC) in Vancouver, Canada, was asked to collaborate with the researchers that led this study. The group is based at the McGill University in Montreal, and it was led by geneticist Jeffrey Mogil. Details of the findings were published in the latest issue of the esteemed scientific publication Nature Methods.

For the new experiments, the team decided to take a test measure designed to assess the levels of pain infants are experiencing and apply it on lab mice. Details obtained with the mouse grimace scale (MGS) showed that the rodents tended to grimace most when faced with pain that lasted for minutes to hours, as well as when their internal organs were affected. The scientists say that the newly-obtained datasets hint at the fact that mice could be used to test for new painkiller medication, given the similar reactions they have when experiencing painful stimuli.