The 2026 Nobel Prize in Physiology or Medicine has been awarded jointly to Karl Deisseroth, Peter Hegemann, and Georg Nagel for pioneering discoveries that transformed neuroscience through the development of optogenetics, a revolutionary technique that allows scientists to control brain cells using light.
The Nobel Committee said the three researchers were recognised for their work on light-gated ion channels and for turning those discoveries into a practical tool that has fundamentally changed how scientists study the brain. Their research has enabled researchers to switch specific nerve cells on or off with exceptional precision, providing new insights into memory, behaviour, movement and neurological disorders.
The breakthrough began when Peter Hegemann and Georg Nagel discovered a light-sensitive protein called channelrhodopsin. They found that the protein could respond to light and alter the activity of cells. This discovery opened the possibility of controlling biological processes using light rather than drugs or electrical stimulation.
Building on that work, Karl Deisseroth introduced the gene responsible for channelrhodopsin into nerve cells from laboratory animals. When exposed to blue light, these cells produced electrical signals, effectively allowing researchers to activate selected neurons at will. Deisseroth later demonstrated that the same technique could work inside the brains of living animals.
The result was the birth of optogenetics, a field that has transformed modern neuroscience. Unlike traditional methods, which often affect large areas of the brain, optogenetics allows scientists to target specific groups of neurons with remarkable accuracy. Researchers can now observe how individual neural circuits influence behaviour, emotion and cognition.
The technology has already contributed to major advances in understanding conditions such as Parkinson’s disease, depression, epilepsy and addiction. While its primary use remains in research, scientists believe the knowledge gained through optogenetics could eventually lead to new therapies for neurological and psychiatric disorders.
The Nobel Committee described the work as a landmark achievement that has given researchers an unprecedented window into the functioning of the living brain, opening entirely new avenues for medical and scientific discovery.