Pain may come in his and hers

Male and female mice use different kinds of cells to respond to pain, a new study shows. The results suggest that if a similar thing happens in people, pain treatments ought to be tailored to men or women.

Scientists knew that after an injury, cells called microglia in the spinal cord spring into action, a process that’s been linked with persistent pain. When scientists shut down microglia in male mice, the animals became less sensitive to a pointy poke. Yet shutting down the cells had no effect on females, Jeffrey Mogil of McGill University in Montreal and colleagues report June 29 in Nature Neuroscience. In females, immune cells called T lymphocytes may carry pain signals, the scientists suggest.

The results may provide an explanation for some of the differences between males’ and females’ responses to pain and also offer a cautionary note for scientists: Experiments on pain should include both sexes, the authors write.