Trio wins medicine Nobel for ‘controlling’ neurons with light

6 OCTOBER 2026

A trio of scientists — Karl Deisseroth, Peter Hegemann, and Georg Nagel —was declared the winners of the 2026 Nobel Prize in Physiology or Medicine for discoveries leading to a technique called optogenetics, which allows scientists to control select nerve cells using light.
The laureates will share the prize, worth 12 million Swedish kronor (₹11.5 crore), equally.
Their discoveries allowed neuroscience to move beyond observing correlations and testing how particular neurons and neural circuits are related to different behaviours and emotions.
Today, optogenetics helps scientists study schizophrenia, depression, Alzheimer’s and Parkinson’s diseases, and test treatments to restore vision and hearing loss.

Hegemann’s discoveries with Chlamydomonas

In the 1990s, Mr. Hegemann, now at Humboldt University in Berlin, and his team found that shining light on a microscopic alga called Chlamydomonas rapidly triggered an electric signal within its body. He reasoned that the molecule involved in detecting light might be, or linked to, a protein that lets certain charged ions enter cells.

Optogenetics technique

The team of Mr. Deisseroth, who is at the Stanford University in U.S., published its first major result in 2005 using rat neurons, and a year later, the technique had its name: optogenetics.
In 2007, Mr. Deisseroth’s group stimulated specific neurons in the brain of live mice with light sent through a slender fibre-optic cable, moving the mice’s whiskers.

Hegemann and Nagel’s experiments

Since then, scientists have used optogenetics to identify networks in the brain involved in pain, attention, sleep, memories, and social behaviours.
Around 2000, Mr. Hegemann approached Mr. Nagel, currently at the University of Würzburg in Germany, who confirmed the idea in an experiment. The team identified two proteins that were channels, and they opened when exposed to light. Mr. Hegemann and Mr. Nagel showed that putting the gene for this protein in mammal cells also made them sensitive to light.
At Stanford University, Mr. Deisseroth realised this discovery could transform the way scientists study the brain. Genetic methods could make sure the protein was associated with a specific set of neurons, while light could turn those neurons on or off.