These mice like to spend time chilling

When breath mints are called “cool” on television, it’s truth in advertising, according to a new study by Sven-Eric Jordt, Ph.D., assistant professor of pharmacology, and colleagues from the University of California at San Francisco and the University of Wisconsin.

The team reports in the July 12 issue of Nature that mouse neurons engineered to lack TRPM8, an ion channel receptor involved in detecting the cooling sensation produced by menthol, were profoundly less sensitive to both menthol and cool temperatures.

In further experiments, when mice lacking TRPM8 were placed on test surfaces that included cool areas, they were far less likely than normal mice to avoid those spots. However, if these areas were cooled below 15 °C (59 °F), TRPM8-deficient mice avoided them as much as normal mice, suggesting that temperatures below this threshold may stimulate pain pathways that do not rely on TRPM8.

The importance of TRPM8 in detecting menthol is well-established, but some researchers disputed its role in cold detection. For now, it seems, the issue’s been iced.