The Nobel Assembly at Karolinska Institutet announced on Monday that Karl Deisseroth, Peter Hegemann, and Georg Nagel are joint winners of the 2026 Nobel Prize in Physiology or Medicine for their work in optogenetics.

The academy announced them as winners of the 2026 Nobel Prize in Physiology or Medicine on Monday, calling them “laureates” whose works “have laid the foundation of a new era in neuroscience”.

“The Nobel Prize in Physiology or Medicine 2026 is awarded for optogenetics — a method that makes it possible to show how nerve cells shape memories, feelings and behaviours in the living brain,” it said. “Peter Hegemann and Georg Nagel discovered a remarkable protein, channelrhodopsin, in a single-celled alga, while Karl Deisseroth transformed the protein into a light-controlled switch for nerve cells.”

“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.

In the early 2000s, Mr Hegemann, senior professor of Neuroscience at Humboldt University of Berlin, Germany and Mr Nagel, a professor of Molecular Plant Physiology at the Department for Molecular Plant Physiology and Biophysics – Botany I, University of Würzburg, Germany, discovered channelrhodopsin, an algal protein with unique properties, found on the surface of the cell.

When blue light illuminates it, the protein opens a channel. Charged ions then flow into the cell, creating an electrical impulse.

“They found that regardless of which cell they put the protein in, those cells became light sensitive,” it said.

Mr Deisseroth, a professor of Bioengineering and of Psychiatry and Behavioural Sciences at the Howard Hughes Medical Institute and Stanford University, “introduced the gene for channel-rhodopsin into nerve cells from rats”.

“By illuminating the cells with blue light, he was able to trigger a nerve signal. He published this breakthrough in 2005. Two years later, he made this light-controlled switch for nerve cells work in the brains of living mice,” the academy said.

The three laureates will share 12 million Swedish kronor that comes with the prestigious award.