Karl Deisseroth, Peter Hegemann and Georg Nagel Win 2026 Nobel Prize in Physiology or Medicine for Optogenetics

Stockholm: The 2026 Nobel Prize in Physiology or Medicine has been jointly awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for their discoveries concerning light-gated ion channels and optogenetics, the Nobel Assembly at Karolinska Institutet announced Monday.

The prize honours the development of optogenetics, a method that makes it possible to show how nerve cells shape memories, feelings and behaviours in the living brain. Per Svenningsson, chair of the Nobel Committee for Physiology or Medicine, said the technique has opened up possibilities for mapping brain activity in ways scientists could previously only imagine.

The development of optogenetics began with a question about how a single-celled alga responds to light, eventually leading to a technique that has transformed research into the brain.

Peter Hegemann was intrigued by how Chlamydomonas swims towards a light source. In the early 2000s, Hegemann and Georg Nagel discovered channelrhodopsin, a protein on the surface of the alga’s cells with unusual properties.

When exposed to blue light, channelrhodopsin opens a channel that allows charged ions to enter the cell, generating an electrical impulse. The researchers found that introducing the protein into different types of cells made those cells sensitive to light.

The discovery was subsequently applied to nerve cells. Karl Deisseroth introduced the gene responsible for channelrhodopsin into rat neurons and showed that blue light could be used to trigger nerve signals. He published the finding in 2005 and, two years later, demonstrated that the technique could be used to control nerve cells in the brains of living mice.

The approach, now known as optogenetics, has since had a significant impact on neuroscience. Researchers have used it to investigate neural circuits associated with specific memories, emotions and behaviours linked to neurological and psychiatric disorders.

The technique is also being explored in clinical medicine, including efforts to restore sight in people with visual impairment.

Optogenetics has fundamentally changed the way scientists study the brain, enabling researchers to investigate its workings with increasing precision and contributing to efforts to understand one of science’s enduring mysteries: how the human brain works.