Karl Deisseroth, Peter Hegemann and Georg Nagel have been awarded the 2026 Nobel Prize in Physiology or Medicine. Announced on 5 October, the prize recognises discoveries behind optogenetics, a method that lets researchers control selected nerve cells with light.
The story began with single-celled algae and a question about how they sense light. Hegemann and Nagel studied a light-sensitive protein called channelrhodopsin. Light causes it to open a channel in the cell membrane, allowing charged particles to pass through and changing the cell’s electrical state.
Deisseroth developed the approach for use in neurons. Scientists introduce a gene for a light-sensitive protein into selected cells, then influence them with pulses of light. The method’s name combines its two foundations: optics and genetics.
For researchers, this offers a way to test the role of particular cells in the brain. They can change the activity of a selected group of neurons and observe how an animal’s behaviour changes. Such experiments help distinguish an association from a causal relationship.
Optogenetics has become a tool for laboratories studying neural circuits. A finding in animals, however, cannot automatically be treated as an established treatment for humans. The prize recognises discoveries and a research method, rather than a universal therapy for brain disorders.
