Trio wins Nobel Prize for brain light technology

Three scientists, including American researcher Karl Deisseroth, have won the 2026 Nobel Prize in Physiology or Medicine for developing a powerful way to study the brain using light.

Deisseroth and German researchers Peter Hegemann and Georg Nagel were honored for discoveries that led to optogenetic therapy, a technique that lets researchers control individual nerve cells with light.

The breakthrough began with a simple question: how does a tiny green alga detect light and move toward it? Hegemann and Nagel identified light-sensitive proteins called channelrhodopsins. Deisseroth later adapted the discovery for brain research.

By adding these proteins to nerve cells, scientists can use flashes of light to activate or silence specific neurons. This gives researchers much greater control over brain circuits involved in movement, memory, and emotions.

The technology could also help medicine, especially in treatments for conditions including neurological disorders and vision loss. In one trial, the approach helped partially restore sight in a man with an inherited retinal disease.

The three laureates will share a prize of $1.2 million (12 million Swedish kronor). A video of Deisseroth telling his children about the award and their reactions has gone viral.