The study, published in the journal “Nature Communications,” is the first to map the complete pathway of cold sensation from the skin to the brain. It confirms that the body uses separate neural circuits dedicated to sensing cold, different from those responsible for warmth, according to “Live Science.” Through a study conducted on mice, researchers traced how cold stimuli on the skin are translated into neural signals that the brain can process. Contrary to the previous belief that all sensations travel via a single pathway, the study showed that cold uses a separate neural circuit.
Researchers used advanced imaging techniques and genetic and behavioral analyses to trace cold signals from the skin to the spinal cord, where the signals are amplified before being sent to the brain. The study identified skin sensors dedicated to responding to temperatures ranging from 15 to 25 degrees Celsius, considered cold. These sensors activate sensory nerve cells that send signals to the spinal cord, where they are amplified by specialized interneurons. In a groundbreaking experiment, when researchers disrupted these cells, the mice stopped responding to cold, highlighting their crucial role.
These sensors partially contributed to researchers receiving the 2021 Nobel Prize in Physiology or Medicine, but the discovery of signal amplification in the spinal cord is a new and significant addition. Duan affirms that this discovery could have promising medical applications, particularly in alleviating cold-related pain for chemotherapy patients, who suffer from painful sensitivity to mild cold. The team also hopes to study how this pathway interacts with other sensory circuits, such as pain and itch, to understand how disorders in these systems affect the body’s heat sensitivity.
This study, conducted on mice, is a first step in mapping sensory circuits. Duan confirms that the results are applicable to humans due to the similarity of neural components between the two. He adds, “There are still many sensory circuits in the brain we do not yet understand, and this study shows how studying them can lead to new and exciting discoveries.”
