- Person
- David Julius
- Lived
- b. 1955
- Field
- Physiology, pain research
- From
- American
The story
David Julius, born in 1955 in Brooklyn to an Ashkenazi Jewish family from Russia, is a professor at the University of California, San Francisco. After his laboratory discovered the nerve sensor for painful heat by studying chili peppers, he turned to the opposite sensation: cold.
The approach was the same. Just as capsaicin makes the mouth feel hot, menthol from mint plants makes it feel cool. Julius reasoned that menthol must act on a sensor that is normally switched on by low temperatures. His team searched sensory neurons for the molecule that responds to menthol and, in a study published in 2002, cloned an ion channel that was activated both by menthol and by cooling. It was named TRPM8, and it is structurally similar to the heat sensor TRPV1.
TRPM8 turned out to be central to how we feel cold. Researchers have reported that it switches on when temperatures drop below about 26 degrees Celsius, and it is now described as the primary molecular sensor of cold in humans. Mice lacking a working version of it are severely impaired at detecting cold. Together with TRPV1 and related channels, it showed that our nerves carry a set of molecular thermometers, each tuned to a different range of temperatures.
The discovery also matters for people in pain. In some nerve injuries, ordinary coolness or a light touch can become painful, a symptom called allodynia. In laboratory studies, mice lacking TRPM8 showed less of this cold and touch sensitivity in models of nerve pain, and blocking TRPM8 reversed established pain in models of nerve and internal organ pain. TRPM8 has also been linked to pain in a bladder condition. Researchers are now seeking drugs that act selectively on TRPM8 as a possible new class of treatments for nerve pain.
Julius and his colleague Yifan Cheng later determined TRPM8's structure, giving drug designers a detailed picture of the molecule they hope to target.
By explaining something as everyday as the cool tingle of mint, Julius's work revealed how the body senses temperature and gave scientists new targets in the long effort to treat chronic pain.
Why it matters
Identifying the body's cold sensor gave researchers a new target for treating nerve pain, including the painful cold sensitivity that follows some nerve injuries.
About David Julius
Brooklyn-born physiologist who used chili pepper and menthol to find the body’s sensors for heat, cold and pain, opening a new path toward pain relief without opioids. Nobel Prize 2021.
More about David Julius
Sources
- Pain Researcher David Julius Wins 2020 Kavli Prize in Neuroscience University of California, San Francisco
- TRPM8 Wikipedia
- David Julius Wikipedia
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.