New Delhi, October 5: The 2026 Nobel Prize in Physiology or Medicine has been awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for discoveries that established the scientific basis of optogenetics, a technique that allows researchers to control the activity of individual nerve cells using light and has transformed the study of the brain.
The Nobel Assembly at Karolinska Institutet in Stockholm announced the award on Monday, highlighting the method’s potential to help scientists understand how the brain produces memories, feelings and behaviours. Optogenetics allows researchers to switch 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.
The breakthrough traces to work by Hegemann and Nagel on light-sensitive proteins. Hegemann’s research examined how certain microorganisms detect light through specialised proteins, while Nagel helped establish that these proteins could operate as light-controlled ion channels.
Their work led to the discovery of channelrhodopsin, a protein with distinctive properties. The researchers found that introducing the protein into different cells made those cells sensitive to light, providing the foundation for controlling cellular activity through illumination.
Deisseroth subsequently introduced the gene for channelrhodopsin into rat nerve cells. Using blue light, he triggered nerve signals in those cells and later developed the technique so the light-controlled mechanism could operate inside the brains of living mice.
The resulting method, known as optogenetics, has gained global use in neuroscience. Researchers have employed it to identify neural circuits associated with specific memories, feelings and behaviours, including circuits relevant to neurological and psychiatric disorders.
The technique has also moved towards potential clinical applications. Researchers are using optogenetics in attempts to restore sight in people with visual impairment, extending its use beyond laboratory studies of brain function.
Deisseroth is a professor of bioengineering, psychiatry and behavioural sciences at Stanford University in the United States. Hegemann is a German biophysicist whose work focused on light-sensitive proteins in microorganisms. Nagel, a German neuroscientist, contributed to the discovery and characterisation of microbial opsins and demonstrated their potential as light-controlled ion channels.
The award recognises a body of work that has enabled scientists to manipulate nerve-cell activity with light, giving researchers a way to investigate the neural mechanisms underlying memory, feelings and behaviour in living brains.
