American Karl Deisseroth and Germans Peter Hegemann and Georg Nagel won the 2026 Nobel Prize in Physiology or Medicine on Monday, Oct. 5, for discoveries about light and optogenetics that have helped explain how the brain works. The Nobel Assembly of Sweden’s Karolinska Institute selected them for their “discoveries concerning light-gated ion channels and optogenetics.”
The three scientists will share a prize of 12 million Swedish crowns, or $1.2 million. Deisseroth is 54, Hegemann is 71 and Nagel is 73. Their award recognizes research that gave scientists a way to control individual nerve cells with light. It’s a major advance.
How the method works
“Optogenetics makes it possible to switch on, or off, the activity of individual nerve cells in a living brain,” Thomas Perlmann, Secretary-General of the Nobel Assembly at Karolinska Institutet, said. “This method is now being used in laboratories around the world to reveal the brain’s mysteries.”
Hegemann began the research with investigations in the early 1990s into how the alga Chlamydomonas responds to light. He studied a response that takes half a millisecond and proposed that a single protein both captured light and acted as an ion channel. Nagel tested the idea by injecting Chlamydomonas genes into frog eggs. The work led the scientists to discover channelrhodopsin-2, an ion channel that opens when exposed to light.
In 2003, Hegemann and Nagel published findings showing that researchers could introduce the protein into human and hamster cells, where light could generate electrical impulses. Two years later, Deisseroth, at Stanford, demonstrated the technique in rat nerve cells. Researchers named the method optogenetics a year later.
Research and possible treatments
Researchers are now studying possible clinical applications. In clinical trials, they’re seeking to restore vision to people blinded by retinitis pigmentosa by inserting a light-sensitive protein into the retina. Researchers also hope optogenetics could improve cochlea implants, enabling more precise stimulation of the auditory nerve than current electrical devices. They haven’t yet established those treatments.
Perlmann said he had spoken to all three laureates that morning and that they were surprised and delighted. “All three said the same thing, that they thought it was absolutely wonderful to receive the prize with the other two and they call them my friends. That it’s such an honour to receive them together. So that’s something they conveyed,” he said.
The physiology or medicine prize traditionally opens the annual Nobel announcements. Awards in physics, chemistry, literature, peace and economics are to follow over the coming days. Expert committees appointed by the prize-awarding institutions choose the laureates. They don’t make the selections themselves.
The Nobel award
Swedish inventor and industrialist Alfred Nobel established the five original Nobel Prizes under his will. They have been awarded since 1901, with limited interruptions, chiefly during World War One and World War Two. Sweden’s central bank, the Riksbank, established the economics prize in 1968.
The medicine prize has previously recognized discoveries including Alexander Fleming’s work on penicillin, recognized in 1945, and Karl Landsteiner’s discovery of human blood groups, for which he won in 1930. Last year, American scientists Mary Brunkow and Fred Ramsdell and Japan’s Shimon Sakaguchi received the medicine prize for work shedding light on how the immune system spares healthy cells, creating openings for possible treatments of diseases such as cancer.
The awards are presented in Stockholm, except for the Peace Prize, which is handed out in Oslo. The article describes that arrangement as a tradition often linked to the union that bound Sweden and Norway during Nobel’s lifetime. Celebrations culminate on Dec. 10, the anniversary of Nobel’s death, when laureates receive their awards at ceremonies attended by Sweden’s and Norway’s royal families and are honored at gala banquets. That date marks Nobel’s death.