The phrase “I feel your pain” takes on new meaning with a study from the Tokyo University of Science that shows when mice hear other mice squeak with pain, they become more sensitive to pain themselves — hurt or not.

These pain squeaks are ultrasonic — way too high-pitched for humans to hear, but perfectly clear to other mice. When researchers played recordings of these cries to healthy mice, the listeners started showing signs of heightened pain sensitivity.

Scientists also found signs of brain inflammation, especially in the thalamus, a region linked to pain processing. Two inflammation genes (Ptgs2 and Cxcl1) lit up, showing that the stress of hearing pain alone can trigger a physical reaction in the brain.

The effect wasn’t just emotional. Mice already suffering from pain took longer to recover and didn’t respond well to painkillers after hearing these sounds. But when researchers used drugs to block those inflammation pathways, the extra pain eased up.

The study is in its infancy, but the results suggest pain might be socially contagious — and that sounds alone can trigger it.

This is a novel way to think about pain, empathy and healing — at least if you’re a mouse.

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