2026 Nobel Prize in Medicine awarded for brain research tool called optogenetics

Karl Deisseroth, Peter Hegemann, and Georg Nagel are the joint recipients of the 2026 Nobel Prize in Physiology or Medicine 'for their discoveries concerning light-gated ion channels and optogenetics,' the Karolinska Institutet announced Monday. Deisseroth, 55, is a professor at the Howard Hughes Medical Institute and Stanford University; Hegemann, 72, is a professor at Humboldt University in Berlin; and Nagel, 73, is a professor at the University of Würzburg, Germany.

Optogenetics uses light combined with genetic modifications of neurons to switch individual cells on or off in a living brain. This makes it possible to show how nerve cells shape memories, feelings, and behavior, and the approach is being studied as a treatment for disease. The work began in the early 1990s at the Max Planck Institute, when Hegemann wondered how a single-cell green alga called Chlamydomonas could swim toward light. Teaming up with Nagel, they found the answer: channelrhodopsin, a light-sensitive ion channel in the cell membrane that rapidly opened when exposed to light. They also found that the protein worked in any cell they injected it into.

Deisseroth then introduced the gene for the protein into nerve cells from rats, making it possible to trigger a nerve signal in the living brain with blue light. That enabled scientists to identify which cells are responsible for which functions and which cells are connected to one another. Per Svenningsson, chair of the Nobel Committee for Physiology or Medicine, said, 'Optogenetics provides opportunities for mapping the brain in a way that we could once only dream of.' Deisseroth told STAT that unlike usual scientific or medical uses of light as an observational tool to collect information, optogenetics is the opposite: 'We're not using light to collect information, we're using light to cause things to happen ... it's using light to turn cells on or off with that millisecond precision and the cellular resolution that is essential to brain function.'

The committee was able to reach all three winners. Deisseroth, the first notified, said, 'It was after midnight, and I was just drifting off to sleep. It was a very unexpected, but of course very delightful call.' He said he had not yet spoken with the others but looked forward to seeing his co-laureates and talking with them. Thomas Perlmann, secretary for the Nobel Committee for Physiology or Medicine, said that when informed of the shared award, 'all three said the same thing, that they thought it was absolutely wonderful to receive the prize with the other two; they called them my friends.' Deisseroth added that the other two were frequent collaborators with whom he had written multiple papers and shared the journey of discovery.