Heat Pain and Cold Pain

Abstract

Noxious cold and noxious heat have detrimental effects on key biological macromolecules and thus on the integrity of cells, tissues, and organisms. Thanks to the action of a subset of somatosensory neurons, mammals can swiftly detect noxiously cold or hot objects or environments. These temperature-sensitive nociceptor neurons become activated when the temperature at their free endings in the skin or mucosae reaches noxious levels, provoking acute pain and rapid avoidance reflexes. Whereas acute temperature-induced pain is essential to prevent or limit burn injury, pathological conditions such as inflammation or tissue injury can deregulate the thermal sensitivity of the somatosensory system, resulting in painful dysesthesias such as heat and cold hypersensitivity. In recent years, important advances have been made in our understanding of the cellular and molecular mechanisms that underlie the detection of painful heat or cold. These research efforts not only provided key insights into an evolutionary conserved biological alarm system, but also revealed new avenues for the development of novel therapies to treat various forms of persistent pain.