On Oct. 4, 2021, the Nobel Prize in Physiology or Medicine was awarded to David Julius and Ardem Patapoutian ‘for their discoveries of receptors for temperature and touch’.

Our ability to sense heat, cold and touch is essential for survival and underpins our interaction with the world around us. In our daily lives we take these sensations for granted, but how are nerve impulses initiated so that temperature and pressure can be perceived? This question has been solved by this year’s Nobel Prize laureates. David Julius utilized capsaicin, a pungent compound from chili peppers that induces a burning sensation, to identify a sensor in the nerve endings of the skin that responds to heat. Ardem Patapoutian used pressure-sensitive cells to discover a novel class of sensors that respond to mechanical stimuli in the skin and internal organs. These breakthrough discoveries launched intense research activities leading to a rapid increase in our understanding of how our nervous system senses heat, cold, and mechanical stimuli. The laureates identified critical missing links in our understanding of the complex interplay between our senses and the environment.

The discovery of TRPV1 was a major breakthrough leading the way to the unravelling of additional temperature-sensing receptors. Independently of one another, both David Julius and Patapoutian used the chemical substance menthol to identify TRPM8, a receptor that was shown to be activated by cold. Additional ion channels related to TRPV1 and TRPM8 were identified and found to be activated by a range of different temperatures. Many laboratories pursued research programs to investigate the roles of these channels in thermal sensation by using genetically manipulated mice that lacked these newly discovered genes. David Julius’ discovery of TRPV1 was the breakthrough that allowed us to understand how differences in temperature can induce electrical signals in the nervous system.