Prestigious prize for pain research
UCSF scientist studying hot, cold receptors wins award
David Julius was shopping with his wife in a San Francisco supermarket about 10 years ago when a shelf full of spices and chili peppers led to his aha! moment.
The UCSF scientist had been puzzling over just how the human nervous system perceives pain from extreme heat or cold or inflammation, and looking at all those hot spices made him think.
“My wife, is a scientist, too,” Julius recalled, “and I was thinking, ‘Wow, those chiles and Tabasco are so interesting,’ and my wife said, ‘Well, why don’t you get off your ass and find out more?’
“Well, she really made me drill down on the problem, so I went back to the lab and we worked on the pain problem for years until we
finally learned just how pain is perceived by specific receptors in our own human nerve endings.”
The discovery has earned Julius the prestigious Canada Gairdner Award, a $100,000 prize that since 1959 has gone to more than 360 scientists — of whom 84 have later won Nobels. The award was to be announced Tuesday in Toronto.
In his laboratory, Julius has used the far simpler nervous systems of animals — like pit vipers, rattlesnakes and tarantulas — to serve as models for discovering how pain sensations reach specific molecules at human nerve endings. Those molecules are proteins known as TRP (pronounced trip) receptors.
The structures that Julius and his colleagues discovered in human nerves that perceive heat are known as capsaicin receptors because the painful heat that scorches the tongue when biting into a habanero or a scorpion chili is due to the chemical called capsicum. The pain from extreme cold reaches molecules in nerve endings called menthol receptors, while the human nerve endings that respond to inflammation are now called the wasabi receptors.
Julius, 66, calls his research “curiosity-driven science.”
His pain studies are entirely funded by America’s National Institutes of Health, and Julius noted that the Trump administration’s budget proposal now calls for cutting $5.8 billion from the NIH’s current budget of $30 billion.
Eighty percent of that money goes for highly competitive research grants to more than 300,000 biomedical scientists at more than 2,500 research institutions.
“I’m worried because it’s the NIH that supports all our work,” he said during a phone interview from Germany, where he has been attending a conference.
“The kind of research we do is very basic, but it’s of interest to many pharmaceutical companies.”
Those companies are are looking for new classes of painkilling drugs that could replace opioids, like morphine, hydrocodone, oxycodone and others responsible for today’s drug abuse epidemic.
Most recently, Julius and two postdoctoral fellows in his lab, Nicholas Bellono and Duncan Leitch, have explored the ability of sea creatures like sharks, skates and rays to hunt for prey by tuning in to faint signs of electric currents from the heartbeats of animals hidden beneath the sand of the sea floor.
The researchers focused on one species called the little skate and traced the detailed mechanisms of the phenomenon, called electrosensation.
“Skates and sharks have some of the most sensitive electroreceptors in the animal world,” Julius said. “So understanding how this works is like understanding how proteins in the eye sense light — it gives us insight into a whole new sensory world.”
Bellono noted that there are striking similarities between the skate’s electrosensory organs and the “hair cells” of the inner ear in humans.
“Understanding the differences,” he said, “could be important for better understanding the (human) auditory system.”
That study, like Julius’ discovery of the TRP receptors, is also entirely supported by research grants from the NIH.
Julius’ wife, Dr. Holly A. Ingraham, is a UCSF professor of cellular and molecular pharmacology, and her research is relevant to age-related diseases in women with varied stages of hormone deficiency. The research in Ingraham’s lab is also supported by the NIH.