Scientists create mouse grimace scale to help identify pain in humans and animals

May 09, 2010

A new study by researchers from McGill University and the University of British Columbia shows that mice, like humans, express pain through facial expressions.

McGill Psychology Prof. Jeffrey Mogil, UBC Psychology Prof. Kenneth Craig and their respective teams have discovered that when subjected to moderate pain stimuli, mice showed discomfort through in the same way humans do. Their study, published online May 9 in the journal , also details the development of a Mouse Grimace Scale that could inform better treatments for humans and improve conditions for lab animals.

Because pain research relies heavily on rodent models, an accurate measurement of pain is paramount in understanding the most pervasive and important symptom of chronic pain, namely spontaneous pain, says Mogil.

"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," says Mogil. "There are also serious implications for the improvement of veterinary care more generally."

This is the first time researchers have successfully developed a scale to measure spontaneous responses in animals that resemble human responses to those same painful states.

Mogil, graduate student Dale Langford and colleagues in the Pain Genetics Lab at McGill analyzed images of mice before and during moderate pain stimuli - for example, the injection of dilute inflammatory substances, as are commonly used around the world for testing in rodents. The level of pain studied could be comparable, researchers said, to a headache or the pain associated with an inflamed and swollen finger easily treated by common analgesics like Aspirin or Tylenol.

Mogil then sent the images to Craig's lab at UBC, where facial pain coding experts used them to develop the scale. Craig's team proposed that five facial features be scored: orbital tightening (eye closing), nose and cheek bulges and ear and whisker positions according to the severity of the stimulus. Craig's laboratory had previously established studying facial expression as the standard for assessing pain in human infants and others with verbal communication limitations. This work is an example of successful "bedside-to-bench" translation, where a technique known to be relevant in our species is adapted for use in laboratory experiments.

Continuing experiments in the lab will investigate whether the scale works equally well in other species, whether analgesic drugs given to mice after surgical procedures work well at their commonly prescribed doses, and whether mice can respond to the facial pain cues of other mice.

Explore further: Novel marker discovered for stem cells derived from human umbilical cord blood

Related Stories

Mice Capable of Empathy

Jul 06, 2006

A new study by McGill University professor of psychology Dr. Jeffrey Mogil shows that the capacity for empathy, previously suspected but unproven even among higher primates, is also evident in lower mammals.

Pain automatically activates facial muscle groups

Oct 27, 2008

A study has found that people who facially express pain in a more intense way are not exaggerating if their perception of a painful stimulation is controlled. The study conducted by Miriam Kunz is published in the November ...

Better tools needed for assessing infant pain

Jun 24, 2008

Currently used pain assessment tools may be underestimating the pain response in infants according to a study published in the open access journal PLoS Medicine this week. Dr Slater and colleagues (University College London ...

Study: Patients often don't report pain

Feb 13, 2006

A Rochester, Minn., study finds more than 20 percent of people with chronic pain don't seek medical help, suggesting many have unmet pain care needs.

Study: Fetuses can't feel pain

Apr 14, 2006

A senior psychologist at Britain's University of Birmingham says he has found good evidence that fetuses cannot feel pain.

Recommended for you

New pain relief targets discovered

6 hours ago

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

Building 'smart' cell-based therapies

7 hours ago

A Northwestern University synthetic biology team has created a new technology for modifying human cells to create programmable therapeutics that could travel the body and selectively target cancer and other ...

Proper stem cell function requires hydrogen sulfide

10 hours ago

Stem cells in bone marrow need to produce hydrogen sulfide in order to properly multiply and form bone tissue, according to a new study from the Center for Craniofacial Molecular Biology at the Herman Ostrow School of Dentistry ...

User comments : 0

More news stories

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...