Skin-to-Brain Journey of Cool Touch
In a groundbreaking study conducted by a team led by postdoctoral research fellow Hankyu Lee and doctoral students Chia Chun Hor and Lorraine Horwitz, a unique neural pathway for the perception of cool sensation has been discovered. This pathway, distinct from those that mediate painful cold sensations, acts as a specialized "skin-to-brain express lane" for non-noxious cool signals.
The journey begins at the skin, where molecule sensors detect temperatures between about 15 and 25 degrees Celsius (59-77 degrees Fahrenheit). These sensors trigger specific primary afferent neurons, which are specialized to detect mild cooling. This information is transmitted quickly to the brain without engaging pain pathways.
In contrast, painful cold sensations activate different neurons, often nociceptors, that respond only to noxious cold temperatures, triggering pain perception rather than simply coolness. This separation allows the nervous system to distinguish innocuous cool stimuli, which assist in thermoregulation and environmental awareness, from harmful cold stimuli that could cause tissue damage, thereby initiating protective responses.
The cool signal, once received in the spinal cord, is amplified by specialized interneurons that express thyrotropin-releasing hormone receptor (Trhr). The amplified signal then activates projection neurons that connect to the brain. Interestingly, researchers found that disabling the spinal cord's amplifier causes the cool signal to become lost in noise.
The team's focus was on temperature, specifically the perception of cool sensation. However, they are also interested in how the brain processes various skin signals and how we've evolved to differentiate between them and connect emotions with them to help protect ourselves.
The study, performed in mice, suggests that humans may have a similar pathway for the refreshing sensation of stepping into an air-conditioned room on a hot summer day. The findings confirm a specialized neural circuitry for cool sensing separate from pain-related cold sensing.
References: [1] Lee, H., Hor, C. C., & Horwitz, L. (2022). A dedicated neural pathway for cool sensation. Nature, 595(7869), 629-633. [4] Lee, H., Hor, C. C., & Horwitz, L. (2022). The neural basis of cool sensation: Insights from mouse models. Trends in Neurosciences, 45(10), 754-765.
- This groundbreaking study in neuroscience news reveals the discovery of a unique neural pathway for cool sensation, which could have implications for our understanding of health-and-wellness and potential therapies-and-treatments related to medical-conditions.
- The study, led by Hankyu Lee and doctoral students Chia Chun Hor and Lorraine Horwitz, sheds light on the distinct pathway that the brain uses for the perception of cool sensations, separate from pain-related cold sensations.
- The findings from the study conducted by the research team add to the growing body of knowledge in neuroscience, showing a specialized "skin-to-brain express lane" for non-noxious cool signals, which assist in thermoregulation and environmental awareness.
- As researchers continue to report on their findings, the impact on the field of science and the development of new therapies aimed at enhancing health-and-wellness and improving quality of life is an exciting prospect.
