This year's Nobel Prize in Physiology or Medicine went to three scientists from the United States and Germany who pioneered optogenetics, a technique that uses light to switch the activity of specific nerve cells in a living brain on and off.
The Nobel Committee at Sweden's Karolinska Institute announced on the 5th that it had selected Karl Deisseroth, 55, a professor at Stanford University, along with Peter Hegemann, 71, a professor at Humboldt University of Berlin, and Georg Nagel, 73, a professor at the University of Würzburg, as the 2026 laureates in physiology or medicine.
The committee said the award recognized "discoveries concerning light-gated ion channels and optogenetics." The three will share a prize of 12 million Swedish kronor, or about 1.6 billion won.
Thomas Perlmann, secretary-general of the Nobel Committee, said the method makes it possible to turn the activity of individual nerve cells on or off in a living brain. He said it is now being used in laboratories around the world to uncover the secrets of the brain.
Optogenetics began in the early 1990s with research seeking to explain how the alga Chlamydomonas responds to light so rapidly. Hegemann hypothesized that a single protein could both detect light and function as an ion channel.
Nagel inserted Chlamydomonas genes into frog egg cells and, through those experiments, discovered channelrhodopsin-2, an ion channel that responds to light. In 2003, the two researchers published findings showing that inserting the protein into human and hamster cells allowed electrical signals to be generated with light. Deisseroth then implemented the technique in mouse nerve cells in 2005, and the name "optogenetics" was coined in 2006.
Reuters said the technique marked a major turning point in brain research because it allowed the function of specific neural circuits to be verified directly. Using optogenetics, Deisseroth activated particular nerve cells in the motor cortex of mice to control whisker movement, and also confirmed that specific nerve cells regulate wakefulness by rousing sleeping mice with light stimulation.
Optogenetics is now used in research on a range of brain disorders, including schizophrenia, Alzheimer's disease, Parkinson's disease, epilepsy and addiction.
Anna Wedell, a professor of molecular medicine at Karolinska Institute, said that understanding which cells are activated in animal models of dementia, epilepsy and addiction shows researchers where to look in human disease.
Therapeutic applications are also under way. One of the most closely watched areas is research on restoring sight in patients who have lost vision to retinitis pigmentosa, a disease in which the rod and cone photoreceptors of the retina are damaged.
Researchers are attempting to deliver visual information to the brain by inserting light-responsive proteins into the healthy retinal cells that remain and stimulating them to activate the optic nerve. Cases in which some patients partially regained vision through optogenetics have already been reported.
In hearing, researchers are also exploring whether the approach could develop into a technology that stimulates the auditory nerve more precisely than existing cochlear implants.
The most advanced clinical programs are a treatment for autism spectrum disorder being developed by the U.S. biotech firm MapLight and a vision-restoration therapy for retinitis pigmentosa from Nanoscope. Both treatments are expected to need more time before they can be used in actual patients.
Starting with the physiology or medicine prize, the Nobel Committee will announce the winners of the physics prize on the 6th, the chemistry prize on the 7th, the literature prize on the 8th, the peace prize on the 9th and the economics prize on the 12th.
