Do you think that pain in animals can be compared to pain in humans? Its important to remember that pain is not a universal expression (like anger, fear, disgust, contempt, happiness, sadness and surprise). That is, the facial expression of pain has not been proven to be consistent across all human beings.
However, according to an article published on the Science Daily website on May 10 of this year, mice showed discomfort through facial expressions in the same way humans do. Research on mice visual pain clues could not only help in assuaging their discomfort, but could lead to new pain relief drugs for humans.
Psychology professor Jeffrey Mogil and UBC psychology professor Kenneth Craig discovered that mice do indeed show discomfort through facial expressions just as humans do. Their study published May 9th in the journal Nature Methods suggested that this new information could improve conditions for lab animals and might possibly aid in pain treatment for humans.
Dr. Mogil suggests that pain research relies on rodent models; therefore, an accurate measure in pain levels is essential in understanding pervasive symptoms of chronic pain, which is spontaneous pain.
Another study conducted by Mogil and his research team back in 2006 demonstrated that the capacity for empathy is evident in lower mammals such as mice. That study showed that mice that co-habitated and were able to see one another established more sensitivity to pain than those tested alone. This is significant because it documented for the first time a form of emotional contagion between animals. Dr. Mogil purports, “Since we know that social interaction plays an important role in chronic pain behavior in humans then the mechanism underlying such effects can now be elucidated; why are we so affected by those around us?”
Dr. Mogil’s dedication has paid off in his collaborated research with Dr. Craig, in developing the Mouse Grimace Scale. According to Mogil, the success of this scale will help forward the development of analgesics for humans and have significant effects on lab animal and veterinary care in general.
The study monitors and takes images of mice before and after moderate pain stimuli, which is quintessential to a human headache easily treated with an anti inflammatory drug such as aspirin. These images, taken at Mogil’s lab, were then sent to Dr. Craig’s team at UBC where facial pain coding experts used them to develop the scale.
Dr. Craig and his team of researches focused on and scored 5 facial expressions among the mice: orbital tightening (eye closing), nose and cheek bulges and ear and whisker positions.
Craig’s laboratory is a leader in studying facial expressions as a standard in assessing pain in human infants where facial expressions are the number one determinant of infant pain. This relates to an earlier blog we wrote about sucrose as an infant pain reliever (although that research was not conducted by Dr. Craig).
Continuing experiments will be undertaken to decide whether the scale can work just as well across species, whether analgesic drugs given to mice after surgical procedures work well at their prescribed doses and whether mice can respond to the facial pain cues of other mice.
Mogil’s study is interesting as it suggests that emotion and certain facial expressions of emotion are universal even across species. Do you believe this is true?
A trip to the zoo to the primate areas seems to have confirmed to me that at least some animals do indeed share emotional expressions with humans. Visiting the zoo with my sister after having read Emotions Revealed was an eye-opening experience. I’m fascinated by this new research. Thanks for the post!