Karl Deisseroth, Peter Hegemann and Georg Nagel have won the 2026 Nobel Prize in Physiology or Medicine for discoveries that laid the foundations of optogenetics, a technique that lets researchers switch the activity of selected nerve cells on or off with light.
The award, announced Monday by the Nobel Assembly at Karolinska Institutet, recognizes work that transformed experimental neuroscience by giving scientists a precise way to test how individual neural circuits influence movement, perception, emotion and behavior. The three laureates will share the 12 million Swedish kronor prize.
How optogenetics changed neuroscience
The breakthrough grew out of research into light-sensitive proteins found in microorganisms. Hegemann and Nagel helped identify and characterize channelrhodopsins, proteins that respond to light by opening ion channels in cell membranes. Deisseroth and his collaborators later showed that genes encoding those proteins could be introduced into neurons so that pulses of light could control when the cells fired.
That combination of genetics and optics became known as optogenetics. Instead of stimulating broad areas of the brain, researchers can target defined cell populations and observe the effects with much greater spatial and temporal precision.
The method is now used across neuroscience laboratories worldwide. It has helped researchers map neural pathways involved in fear, reward, movement, memory and other functions, and it has also shaped work on neurological and psychiatric disorders. Clinical applications remain more limited than the technique’s research use, but scientists are testing light-sensitive systems in areas including inherited vision loss and other nervous-system conditions.
A prize for a tool that opened the brain
The 2026 medicine award is notable because it honors not a single disease treatment, but a platform that changed how researchers investigate the living brain. Nature described optogenetics as a long-anticipated Nobel contender because of the way it allowed scientists to move from observing neural activity to directly testing cause and effect.
The medicine prize opens Nobel week, with awards in physics, chemistry, literature, peace and economic sciences to follow.
