Karl Deisseroth, a psychiatrist and neuroscientist at Stanford University and the Howard Hughes Medical Institute, is one of three winners of the 2026 Nobel Prize in Physiology or Medicine, announced Monday by the Nobel Assembly at Karolinska Institutet in Sweden.
He shares the prize with German scientists Peter Hegemann of Humboldt University of Berlin and Georg Nagel of the University of Würzburg “for their discoveries concerning light-gated ion channels and optogenetics,” a method that shows how nerve cells shape memories, feelings and behaviors in the living brain.
A light switch for the brain
Hegemann and Nagel discovered channelrhodopsin, a protein in the single-celled alga Chlamydomonas that opens a channel when hit by blue light, letting charged ions flow into the cell and create an electrical impulse. Deisseroth put the gene for the protein into rat nerve cells and triggered nerve signals with blue light, publishing the breakthrough in 2005; two years later he made the switch work in the brains of living mice.
The method has helped researchers uncover neural circuits behind specific memories, feelings and behaviors linked to neurological and psychiatric disorders, and is being used in attempts to restore sight in people with visual impairment. “Optogenetics provides opportunities for mapping the brain in a way that we could once only dream of,” said Per Svenningsson, chair of the Nobel Committee for Physiology or Medicine.
Deisseroth, born in 1971, earned his Ph.D. and M.D. at Stanford. The three laureates will share the prize of 12 million Swedish kronor equally.
