The 2026 Nobel Prize in Physiology or Medicine was awarded on Monday, October 5, to three scientists who developed optogenetics, a technique that uses light to switch individual nerve cells on and off in a living brain.

The winners are Karl Deisseroth, 54, of Stanford University in the United States, Peter Hegemann, 71, of Humboldt University of Berlin, and Georg Nagel, 73, of the University of Würzburg in Germany.

Hegemann and Nagel are credited with discovering channelrhodopsins, light-sensitive proteins found in algae that act as channels in the cell membrane. Deisseroth showed how to place those proteins in neurons, so that a flash of light can activate or silence a chosen group of cells.

The method lets researchers test what specific cells do, and it has changed the study of learning, fear, addiction and movement. “Optogenetics has fundamentally altered our understanding of the brain,” the Nobel Assembly at Sweden's Karolinska Institute said.

The technique is also being studied as a treatment. One possible use is in cochlear implants, where light could stimulate the hearing nerve more precisely than electricity.

The three laureates share 12 million Swedish crowns, about $1.2 million.

The Nobel announcements continue with physics on Tuesday, chemistry on Wednesday, literature on Thursday and the Peace Prize on Friday in Oslo. The prizes are presented on December 10.