The 2026 Nobel Prize in Physiology or Medicine has been awarded to Karl Deisseroth of the Howard Hughes Medical Institute and Stanford University in the United States, Peter Hegemann of Humboldt University of Berlin, Germany, and Georg Nagel of the University of Würzburg, Germany. They were jointly awarded the prize for their discoveries concerning light-gated ion channels and optogenetics. The Nobel Assembly at Karolinska Institutet announced the laureates in its press release dated October 5, 2026.
The trio were recognised for their work that laid the foundation of a new era in neuroscience by enabling researchers to investigate how nerve cells shape memories, feelings and behaviours in the living brain. The breakthrough centres on optogenetics, a technique that uses light to control the activity of nerve cells. This technique has become an important tool in neuroscience research, allowing researchers to identify neural circuits involved in specific memories, feelings and behaviours.
The work began with Hegemann’s efforts to understand how Chlamydomonas, a single-celled alga, swims towards light. In the early 2000s, Hegemann and Nagel discovered channelrhodopsin, a protein found on the surface of the alga. When it is illuminated by blue light, a channel opens through the protein, allowing charged ions to flow into the cell and creating an electrical impulse.
The scientists also found that when the protein was introduced into other cells, those cells became sensitive to light. Deisseroth subsequently took the discovery into neuroscience, introducing the gene for channelrhodopsin into rat nerve cells and using blue light to trigger nerve signals. He published this breakthrough in 2005 and made the light-controlled switch for nerve cells work in the brains of living mice two years later.
The technique, now known as optogenetics, has since been used to identify neural circuits involved in specific memories, feelings and behaviours, including those relevant to neurological and psychiatric disorders. Researchers are also using the method in attempts to restore sight in people with visual impairment. According to Svenningsson, Chair of the Nobel Committee for Physiology or Medicine, optogenetics provides opportunities for mapping the brain in a way that researchers previously could only imagine.
Before these discoveries, scientists could identify brain areas associated with particular functions but struggled to establish causal relationships. The image they developed of the brain was like a sketch map, full of question marks and unknowns. The committee said optogenetics had fundamentally changed that picture, allowing for new discoveries that help solve one of humanity’s great mysteries: how our incredible brain works.
The 2026 Nobel Prize in Physiology or Medicine is the first of this year’s Nobel prizes to be announced. The prize sum has been raised to $1.27m for 2026. This award is a significant recognition of the contributions of Deisseroth, Hegemann, and Nagel to the field of neuroscience, and their work is expected to continue to have a significant impact on our understanding of the brain and its functions.
Key points
- The Nobel Prize in Physiology or Medicine was awarded to Karl Deisseroth, Peter Hegemann, and Georg Nagel for their discoveries concerning light-gated ion channels and optogenetics.
- Optogenetics has become an important tool in neuroscience research, allowing researchers to identify neural circuits involved in specific memories, feelings and behaviours.
- The technique has the potential to be used in attempts to restore sight in people with visual impairment.
