A dedicated skin-to-brain circuit for cool sensation in mice

Summary

Researchers at the University of Michigan have illuminated a complete sensory pathway showing how the skin communicates the temperature of its surroundings to the brain. This discovery, believed to be the first of its kind, reveals that cool temperatures get their own pathway, indicating that evolution has created different circuits for hot and cold temperatures. This creates an elegant solution for ensuring precise thermal perception and appropriate behavioral responses to environmental changes, said Bo Duan, senior author of the new study. "The skin is the body's largest organ. It helps us detect our environment and separate, distinguish different stimuli," said Duan, a U-M associate professor of molecular, cellular, and developmental biology. "There are still many interesting questions about how it does this, but we now have one pathway for how it senses cool temperatures. This is the first neural circuit for temperature sensation in which the full pathway from the skin to the brain has been clearly identified." This work deepens our understanding of fundamental biology and brings us closer to an explanation for how we evolved to inhabit safe temperatures and avoid dangerous extremes, Duan said. But it also has medical implications that can be explored to help improve the quality of life for people in the future. For example, more than 70% of people who have undergone chemotherapy experience pain caused by cool temperatures, Duan said. The new study found that the neural circuit responsible for sensing innocuous cool does not mediate this type of cold pain. But, in understanding how the cool-sensing circuitry works when it's functioning properly under normal conditions, researchers now have a better chance of discovering what goes wrong in disease or injury. It could also help develop targeted therapies that restore healthy sensation without impairing normal temperature perception. This research was funded by the National Institutes of Health and performed in col...