STOCKHOLM  –  The 2026 Nobel Prize in physiology or medicine has been awarded to three scientists – Karl Deisseroth, Peter Hegemann and Georg Nagel for their work developing a technique to decode the inner workings of the brain. This method known as optogenetics acts as a “light-sensitive switch,” allowing scientists to “map which cells are responsible for which function” in the brain, said Anna Wedell, a member of the Nobel Prize committee, which announced the prestigious honour in Sweden on Monday. German researchers Hegemann, 71, and Nagel, 73, discovered a protein in algae, known as channelrhodopsin, before American scientist Deisseroth, 54, “transformed the protein into a light-controlled switch for nerve cells,” the committee said in a statement. That work has “laid the foundation for a new era in neuroscience,” the committee added. By using this method, researchers can identify and even control the neural circuits that govern “specific memories, feelings, and behaviors relevant for neurological and psychiatric disorders.”

Two of the laureates have shared their surprise to winning this year’s prize. Deisseroth had been working on a paper and only just gone to bed when the Nobel committee called him to give him the good news, he said in a telephone interview shared on the Nobel Prize website.

“Now I don’t think I’ll be able to sleep for quite a while,” he added.

Nagel, meanwhile, spoke of his surprise at learning he was a recipient this year while “on the terrace, in the sun” in Italy. “I didn’t expect this, really!” he said. “I have some friends who always say they are watching what’s happening in October when they are announcing it, and I always told them ‘Keep cool.’ There’s only, so far, I know of one patient who profited from optogenetics so … I thought it’s still too early to get this prize in medicine.”