Karl Deisseroth, Peter Hegemann, and Georg Nagel won the 2026 Nobel Prize in Physiology or Medicine on October 5 for discovering light-gated ion channels and optogenetics, a technique that lets researchers control nerve cells with light.
Laureates Win for Light-Gated Ion Channels and Optogenetics
The Nobel Assembly at Karolinska Institutet in Stockholm awarded the prize for their discoveries concerning light-gated ion channels and optogenetics. Peter Hegemann and Georg Nagel discovered channelrhodopsin, a specialized protein found on the surface of a single-celled alga called Chlamydomonas, which allowed the organism to swim toward light.
When illuminated with blue light, the protein opens a channel that lets charged ions flow into the cell, generating an electrical impulse. Hegemann and Nagel demonstrated that introducing this protein into various cells makes those cells sensitive to light. Karl Deisseroth then took the discovery a step further.
Deisseroth introduced the gene for channelrhodopsin into rat nerve cells, triggering nerve signals using blue light. He subsequently demonstrated that this light-controlled switch could be used to control nerve cells in the brains of living mice. The Howard Hughes Medical Institute and Stanford University researcher transformed an algal curiosity into a precise neuroscience tool.
“Optogenetics makes it possible to switch on, or off, the activity of individual nerve cells in a living brain. This method is now being used in laboratories around the world to reveal the brain’s mysteries”
The Nobel Assembly
Optogenetics Unlocks Neural Circuits
Per Svenningsson, chair of the Nobel Committee for Physiology or Medicine, noted that optogenetics provides opportunities for mapping the brain in a way that we could once only dream of.
Laboratories across the globe now use the technique to study neural circuits that govern specific memories, feelings, and behaviors in the living brain.
Laureates Share 12 Million Swedish Kronor Prize
The three laureates share a prize sum of 12 million Swedish kronor, equivalent to about $1.2 million. Peter Hegemann was born in 1954 and Karl Deisseroth was born in 1971 holding a Ph.D. and MD from Stanford University.
| Laureate | Institution | Country |
|---|---|---|
| Karl Deisseroth | Howard Hughes Medical Institute and Stanford University | USA |
| Peter Hegemann | Humboldt University of Berlin | Germany |
| Georg Nagel | University of Würzburg | Germany |
The Nobel Assembly at Karolinska Institutet selects the winners of the Physiology or Medicine prize. The assembly includes 50 voting members who are professors in medical subjects at Karolinska Institutet in Stockholm, operating through a Nobel Committee whose members are elected for three-year terms. This year’s announcement on Monday, October 5, marks the 117th time the Medicine prize has been awarded since 1901, following 116 previous awards to 232 individuals through 2025. Follow the announcement week as Physics is awarded on Tuesday, Chemistry on Wednesday, Literature on Thursday, the Nobel Peace Prize on Friday, and the Nobel Memorial Prize in Economic Sciences on October 12.