Daijiworld Media Network - New Delhi
New Delhi, Oct 5: The 2026 Nobel Prize in Physiology or Medicine has been awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for their discoveries concerning light-gated ion channels and optogenetics, a technique that has transformed the study of the brain, the Nobel Assembly at Karolinska Institutet in Stockholm announced on Monday.
Understanding how the brain forms memories, feelings and behaviours has long been a major goal for researchers. Optogenetics has made it possible to switch the activity of individual nerve cells on or off in a living brain.

"Optogenetics provides opportunities for mapping the brain in a way that we could once only dream of," said Per Svenningsson, Chair of the Nobel Committee for Physiology or Medicine.
According to the official statement, Hegemann and Nagel discovered "channelrhodopsin", a protein with unique properties. They found that irrespective of the type of cell into which the protein was introduced, the cells became sensitive to light.
Deisseroth subsequently introduced the gene for channelrhodopsin into nerve cells from rats. By illuminating the cells with blue light, he was able to trigger a nerve signal. He later demonstrated that the light-controlled switch could be used to control nerve cells in the brains of living mice, the statement said.
The method of controlling nerve signals with light is now known as optogenetics and has rapidly gained global significance.
Hegemann's research helped establish how certain microorganisms sense light through specialised proteins, while Nagel subsequently helped demonstrate that these proteins could function as light-controlled ion channels.
Using optogenetics, researchers have been able to identify neural circuits involved in specific memories, feelings and behaviours, providing insights relevant to neurological and psychiatric disorders.
In clinical medicine, the technique is also being studied as a possible means of restoring sight in people with visual impairment.
Deisseroth is a professor of bioengineering, psychiatry and behavioural sciences at Stanford University in the US.
Hegemann, a German biophysicist, studied light-sensitive proteins in microorganisms, while Nagel, a German neuroscientist, contributed to the discovery and characterisation of microbial opsins and demonstrated their potential to function as light-controlled ion channels.