US scientist Karl Deisseroth has won the 2026 Nobel Prize in Physiology or Medicine alongside German scientists Peter Hegemann and Georg Nagel for discoveries that led to optogenetics.
The technique allows researchers to control nerve cells using light, making it possible to study how individual neurons influence functions such as memory, emotions and behaviour.
Hegemann and Nagel discovered channelrhodopsin, a light-sensitive protein found in a single-celled alga. The protein responds to light by controlling the movement of ions across a cell membrane.
Deisseroth later adapted the discovery for use in nerve cells, developing methods that turned the protein into a light-controlled switch. Using genetic techniques, researchers can introduce these proteins into selected neurons and then activate or inhibit them with pulses of light.
This has allowed scientists to investigate neural circuits while observing the activity of specific groups of neurons. The approach has also given researchers greater precision when studying how individual nerve cells contribute to brain function.
The Nobel committee said the three scientists had laid the foundation for a new era in neuroscience by providing a way to examine the role of individual nerve cells with greater precision.
Deisseroth is a professor at Stanford University. Hegemann is based at Humboldt University of Berlin, while Nagel is a professor at the University of Würzburg.
The prize was announced at the Karolinska Institute in Stockholm on October 5. The three laureates will share the Nobel Prize equally.
