Two American researchers won the 2021 Nobel Prize in Physiology or Medicine for work that uncovered the secrets of the sense of touch.
Professor David Julius, a physiologist at the University of California, San Francisco, and Professor Ardem Patapoutian, a neuroscientist at Scripps Research in La Jolla, California, were honored for their discovery of receptors in the skin that detect heat, cold, and heat. touch. they are crucial for survival.
The award, announced Monday by the Nobel assembly at the Karolinska Institute in Stockholm, is worth 10 million Swedish crowns (£ 845,000), which will be shared equally among the winners.
Professor Abdel El Manira, a neuroscientist at the Karolinska Institute and a member of the Nobel committee, said that without the receptors we would not be able to feel our world, feel the need to lift our hand from a flame, or even stand. The discoveries, he said, had “profoundly changed our view of how we perceive the world around us.”
“For the last year we have been distancing ourselves socially, we have missed the sense of touch, the feeling of warmth that we give each other during a hug,” he added. “And during a hug, these are the receptors that give us a feeling of warmth, of closeness.”
Through experiments that began in the 1990s, scientists reconstructed how nerve impulses are triggered in the skin so that temperature and pressure can be sensed.
Julius turned to capsaicin, the compound that makes chili peppers burn, to identify sensors in the skin’s nerve endings that respond to heat. Meanwhile, Patapoutian studied pressure-sensitive cells and discovered more receptors that respond to punctures and pricks.
The first breakthrough came when Julius and his collaborators created a library of millions of DNA strands that corresponded to genes in sensory nerve cells. Through painstaking effort that involved adding genes one at a time to cells that don’t normally react to capsaicin, they finally identified a single gene that made cells respond to the burning compound. The gene allowed cells to build a protein called TRPV1, which was found to respond to heat perceived as painful.
Working independently of each other, Julius and Patapoutian used menthol to discover a receptor for detecting cold, called TRPM8, and many others activated by a range of different temperatures.
Following its success, Patapoutian and his colleagues set out to understand how cells respond to touch. Through more painstaking experiments on 72 genes, they found one that allowed cells to respond, with a small electrical signal, when prodded with a micropipette.
The gene carried the blueprints of a receptor that scientists called Piezo1, after the Greek word for pressure. Soon after, they found a similar touch-sensitive receptor, Piezo2, that had a second critical function of sensing body position and movement, or proprioception.
Professor Patrick Haggard, UCL Institute for Cognitive Neuroscience, said: “Julius and Patapoutian have demonstrated, in beautiful mechanical detail, how the full range of different bodily sensations works. His research brilliantly reveals how the different sensory qualities we experience every day, such as temperature and touch, each correspond to a specific individual molecule or set of molecules embedded in the membranes of sensory neurons found throughout the world. body.
“His work on temperature sensations is particularly stimulating. Temperature is a unique physical continuum, but we experience it through two different sensory systems, one for heat and one for cold, each dependent on a distinctive molecule.
“The idea that the feeling of cold is ultimately reduced to the presence of the TRPM8 molecule is simply fascinating: it is the closest scientists have come to a truly mechanistic understanding of our own conscious experiences.”
The 2021 Nobel Prize in Physics will be announced on Tuesday, followed by the Chemistry Prize on Wednesday.