A study published recently in Nature Neuroscience suggests that male and female mice process pain using different cells.

These findings reportedly may have far-reaching implications for one’s basic understanding of pain, how the next generation of medications for chronic pain are developed, and how biomedical research using mice is executed.

“Research has demonstrated that men and women have different sensitivity to pain and that more women suffer from chronic pain than men, but the assumption has always been that the wiring of how pain is processed is the same in both sexes,” says co-senior author Jeffrey Mogil, PhD, EP Taylor Professor of Pain Studies at McGill University and Director of the Alan Edwards Centre for Research on Pain, in a news release from McGill University.

“The realization that the biological basis for pain between men and women could be so fundamentally different raises important research and ethical questions if we want to reduce suffering,” Mogil continues.

Mogil and his team from McGill University, as well as research teams from The Hospital for Sick Children (SickKids) and Duke University, conducted the research to analyze the long-standing theory that pain is transmitted from the site of injury or inflammation through the nervous system using an immune system cell called microglia, the release explains.

The teams’ research suggests that this is true only in male mice. Per the release, interfering with the function of microglia effectively blocked pain in male mice, but had no effect in female mice.

Instead, the researchers note in the release, a completely different type of immune cell, called T cells, are responsible for transmitting pain in female mice. Exactly how they do this is unknown.

“Understanding the pathways of pain and sex differences is absolutely essential as we design the next generation of more sophisticated, targeted pain medications,” says Michael Salter, MD, PhD, Head and Senior Scientist, Neuroscience & Mental Health at SickKids and Professor at The University of Toronto, the other co-senior author, in the release.

“We believe that mice have very similar nervous systems to humans, especially for a basic evolutionary function like pain, so these findings tell us there are important questions raised for human pain drug development,” Salter continues.

According to the release, this discovery comes on the heels of the new policy issued by the US National Institutes of Health to require the use of female animals and cell lines in preclinical research.

“For the past 15 years, scientists have thought that microglia controlled the volume knob on pain, but this conclusion was based on research using almost exclusively male mice,” Mogil says in the release.

“This finding is a perfect example of why this policy, and very carefully designed research, is essential if the benefits of basic science are to serve everyone,” he explains.

[Source(s): McGill University, EurekAlert]