May 19, 2022

Two American scientists have been awarded the 2021 Nobel Prize in Physiology or Medicine for unraveling the microscopic mysteries of the human sense of touch.

David Julius of the University of California, San Francisco received half of the prize for his work with “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,” while Ardem Patapoutian of the Scripps Research Institute, received the other half for his work with “pressure-sensitive cells to discover a novel class of sensors that respond to mechanical stimuli in the skin and internal organs.”

Their discoveries “have allowed us to understand how heat, cold and mechanical force can initiate the nerve impulses that allow us to perceive and adapt to the world around us,” the Nobel Committee stated in a statement. “This knowledge is being used to develop treatments for a wide range of disease conditions, including chronic pain.”

The prize is ten million Swedish kronor ($1.15 million), which will be split equally between the two winners.

The scientists began piecing together the chemical pathways that convert heat and pressure detected on the skin into nerve impulses perceived by the brain in the 1990s. Julius and his colleagues began by compiling a database of millions of DNA segments encoding genes identified in sensory nerve cells. They eventually discovered that a single gene was responsible for the burning sensation associated with capsaicin by introducing the genes one by one to cells that did not ordinarily react to capsaicin. The gene they uncovered enabled cells to synthesize a protein called TRPV1, which was activated at painfully hot temperatures.

Julius and Patapoutian independently discovered another protein, TPRM8, activated by cold temperatures and a variety of additional proteins that detected a range of temperatures.

Not only did the discoveries shed light on the mechanics underlying sensory experiences like warmth and pressure, but they also opened the door to a new class of medications targeting the receptors — ranging from painkillers to those that may lower blood pressure in blood arteries and organs.

“While we understood the physiology of the senses, what we didn’t understand was how we sensed differences in temperature or pressure,” Oscar Marin, head of King’s College London’s MRC Centre for Neurodevelopmental Disorders, told The Associated Press. “Knowing how our body senses these changes is fundamental because once we know those molecules, they can be targeted. It’s like finding a lock, and now we know the precise keys that will be necessary to unlock it.”

In 1944, Joseph Erlanger and Herbert Gasser received the Nobel Prize in physiology or medicine for discovering specialized nerve cells that respond to both painful and non-painful touch.