Scientists win Nobel Prize for light-based brain cell control discovery

Three scientists have won the 2026 Nobel Prize in Physiology or Medicine for discovering how to control brain cells with light. Peter Hegemann, Georg Nagel, and Karl Deisseroth share the award for their work on optogenetics.

Hegemann and Nagel studied a tiny alga called Chlamydomonas. This simple organism has no brain or eyes, but it can sense light and move toward it. The scientists found that the alga uses a protein called channelrhodopsin to turn light into electrical signals. This protein sits in the cell membrane and contains a molecule that reacts to light.

Deisseroth used this discovery to develop optogenetics, a technique that lets researchers switch individual brain cells on and off using light. Scientists have already used it to activate memories and may one day use it to treat brain disorders and restore lost vision.