How do we feel the heat or the cold?
This question was answered, earning it Massachusetts’ highest scientific honor.
Over the past four decades, Dr. David Julius has risen to the top of the field of physiology, leading the physiology department of a major university, making groundbreaking advancements in understanding our sense of touch and sharing a Monday a Nobel Prize for these discoveries.
But before all of that, he was one of the thousands of Boston-area undergraduates.
Julius, 65, graduated from Massachusetts Institute of Technology in 1977 with a bachelor’s degree in life sciences, according to his staff biography at the University of California at San Francisco.
He traveled across the country to earn a graduate degree in biochemistry at UC Berkeley before returning to the East as a postdoctoral researcher at the University of Colombia. There, says his biography page, he developed a new method of “cloning expressionsWhich consists of isolating the genetic code based on the specific proteins it affects.
But since joining UCSF in 1989, a central focus of Julius’ work has been trying to understand our senses of pain and touch at the molecular level.
He has discovered a family of “temperature-sensitive ion channel receptors”, according to the university, “which allow sensory nerve fibers to sense hot or cold temperatures.”
It is thanks to this work that Julius received this year the Nobel Prize in Physiology or Medicine, sharing it with Dr Ardem Patapoutian of the Scripps Research Institute, in La Jolla, California
“Our ability to feel heat, cold and touch is essential to our survival and underpins our interaction with the world around us,” the Nobel committee said in its announcement of the award. “In our daily life, we take these sensations for granted, but how are nerve impulses initiated so that temperature and pressure can be felt? This question has been answered by this year’s Nobel Laureates.
Using capsaicin, a compound found in chili peppers that induces a burning sensation, Julius located the sensor in nerve endings that reacts to heat, the Nobel committee said. Patapoutian discovered a type of sensor that reacts to touching the skin and internal organs.
Julius and his team have created a library of millions of DNA fragments corresponding to genes that affect pain, heat sensing, and touch. The library, they speculated, would include DNA that builds a protein that reacts to capsaicin, the committee said.
By testing genes throughout the library, the team finally found only one that could make cells sensitive to capsaicin and identified the protein associated with it. By studying the protein’s ability to react to heat, the committee said, Julius realized he had found “a heat-sensing receptor that is activated at temperatures perceived to be painful.”
Patapoutian’s team first discovered cells that emit electrical signals when stimulated. By turning off certain genes that could trigger the reaction, they were able to isolate those that make cells sensitive to touch. In doing so, the researchers have better explained how our cells feel and sense the things we come into contact with.
“These groundbreaking discoveries initiated intense research activity leading to a rapid increase in our understanding of how our nervous system senses heat, cold and mechanical stimuli,” said the Nobel announcement. “The winners identified critical missing links in our understanding of the complex interplay between our senses and the environment. “