Karl Deisseroth, Peter Hegemann, and Georg Nagel win 2026 Nobel Prize in Physiology or Medicine

American scientist Karl Deisseroth and Germans Peter Hegemann and Georg Nagel have won the 2026 Nobel Prize in Physiology or Medicine for their pioneering discoveries on light and optogenetics that have helped understand how the brain works.

The Nobel Assembly of Sweden’s Karolinska Institute medical university said on Monday that Deisseroth, 54, Hegemann, 71, and Nagel, 73, were honoured “for their discovery of a molecular switch for nerve cells”.

Optogenetics involves controlling nerve signals with light, and helps researchers understand how specific cell types contribute to behaviours like learning, fear, addiction and movement.

“Optogenetics has fundamentally altered our understanding of the brain. Every day brings new discoveries, helping to solve one of humanity’s great mysteries: how our incredible brain works,” the Nobel Assembly said.

Thomas Perlmann, the secretary-general of the Nobel Assembly at Karolinska Institute, added that optogenetics “makes it possible to switch on, or off, the activity of individual nerve cells in a living brain”.

“This method is now being used in laboratories around the world to reveal the brain’s mysteries,” Perlmann added.

“Optogenetics provides opportunities for mapping the brain in a way that we could once only dream of,” Per Svenningsson, chair of the Nobel committee, said in a statement.

Researchers also hope optogenetics could improve cochlear implants, allowing more precise stimulation of the auditory nerve than current electrical devices.

Deisseroth, 54, is a professor at Stanford University in the US, while Hegemann, 71, is a neuroscience professor at Humboldt University of Berlin. Nagel, 73, is a biophysics professor at the University of Wurzburg. The three of them will share a prize sum amounting to 12 million Swedish crowns ($1.2m).

“All three said the same thing: that they thought it was absolutely wonderful to receive the prize with the other two who they call their friends – that it’s such an honour to receive the prize together,” Perlmann said.

Nobel laureates are chosen by expert committees appointed by the prize-awarding institutions. The physiology or medicine prize traditionally opens the annual Nobel announcements, with the Nobel Prize for physics announced on Tuesday, followed by the chemistry prize on Wednesday and the literature prize on Thursday.

But perhaps the most keenly anticipated award is that due on Friday, the peace prize – the only Nobel to be awarded in Oslo. Experts have suggested the jury could choose a laureate this year who enjoys broad consensus, after last year’s controversial winner, Venezuelan opposition leader Maria Corina Machado.

Laureates receive their awards on December 10, the anniversary of Nobel’s death, in ceremonies attended by Sweden’s and Norway’s royal families, with banquets held in their honour.