The Nobel Assembly awarded the 2026 medicine prize to Karl Deisseroth, Peter Hegemann and Georg Nagel for light-gated ion channels and optogenetics, a method that uses light to control nerve cells.
American Karl Deisseroth and Germans Peter Hegemann and Georg Nagel won the 2026 Nobel Prize in Physiology or Medicine on Monday for discoveries on light-gated ion channels and optogenetics.
The Nobel Assembly at Karolinska Institutet in Stockholm said the three were chosen for work that lets researchers switch individual nerve cells on or off with light. They will share 12 million Swedish crowns, about $1.2 million. Deisseroth, 54, is at Stanford University. Hegemann, 71, is at Humboldt University in Berlin, and Nagel, 73, is at the University of Würzburg.
The technique grew out of Hegemann's study of how the alga Chlamydomonas responds to light. With Nagel, he identified a protein, channelrhodopsin-2, that opens an ion channel when struck by blue light. Putting that protein into other cells makes them light-sensitive. At Stanford, Deisseroth later showed the method in mammalian nerve cells; the approach was named optogenetics in 2006.
Thomas Perlmann, secretary-general of the Nobel Assembly, said optogenetics makes it possible to switch the activity of individual nerve cells in a living brain and is now used in laboratories worldwide. Reuters reported that Perlmann said all three laureates were surprised and delighted and described one another as friends. Anna Wedell, professor of molecular medicine at Karolinska, said mouse models of dementia, epilepsy and addiction can show which cells are active and where to look in humans.
The medicine prize opens Nobel week. Physics, chemistry, literature, peace and economics awards follow in the coming days.