American scientist Karl Deisseroth has won the 2026 Nobel Prize in Physiology or Medicine along with German scientists Peter Hegemann and Georg Nagel. They were honoured for their work on light-gated ion channels and optogenetics, a method that helps scientists understand how the brain works.
The Nobel Assembly at Sweden’s Karolinska Institutet chose the three scientists for their work on how light can control nerve cells, Reuters reported. In simple terms, it is a technique that combines light and genetics to control specific cells. Scientists introduce light-sensitive proteins into nerve cells. When light is directed at those cells, the proteins react and can change the electrical activity of the cells. This has given scientists a new way to study the brain. The story of optogenetics began with research on algae. In the early 1990s, Peter Hegemann studied how the single-celled alga Chlamydomonas responds to light. It was found to be an ion channel that opens when exposed to light.
Deisseroth is 54 years old. Hegemann is 71, while Nagel is 73. That research led to the discovery of channelrhodopsin-2.
Because it allows scientists to control individual nerve cells using light, their discovery is important.
Thomas Perlmann, Secretary-General of the Nobel Assembly at Karolinska Institutet, said optogenetics can turn individual nerve cells in a living brain on or off. Instead of simply observing brain activity, researchers can activate or silence specific nerve cells and then study what happens, according to Reuters. This became a key part of the technology that later developed into optogenetics, according to Reuters.
