The 2026 Nobel Prize in Physiology or Medicine has been awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for their discoveries of light-gated ion channels and the development of optogenetics, a technique that has transformed the study of the brain. The Nobel Assembly at Karolinska Institutet in Stockholm announced the award on Monday, recognising the scientists’ work that has enabled researchers to control the activity of individual nerve cells using light.
Understanding how the brain creates memories, feelings and behaviours has long been one of neuroscience’s biggest challenges. Optogenetics has opened a new way of studying these processes by allowing scientists 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 back to the work of Hegemann and Nagel, who studied how certain microorganisms detect light. Their research led to the discovery and characterisation of channelrhodopsin, a light-sensitive protein with unusual properties.
The scientists found that when the protein was introduced into different types of cells, those cells became sensitive to light. This finding laid the foundation for using light to control cellular activity.
Deisseroth later took the discovery into neuroscience. He introduced the gene for channelrhodopsin into nerve cells taken from rats and showed that blue light could trigger a nerve signal. He subsequently demonstrated that the same light-controlled switch could be used to control nerve cells inside the brains of living mice.
The approach became known as optogenetics and quickly gained worldwide importance in brain research.
By giving researchers precise control over selected nerve cells, optogenetics has helped uncover neural circuits involved in specific memories, feelings and behaviours. The technique has also provided new insights into brain processes linked to neurological and psychiatric disorders.
Its potential extends beyond research. Scientists are now exploring optogenetics as a possible way of restoring sight in people with visual impairment, highlighting the technique’s growing importance in clinical medicine.
Deisseroth is a professor of bioengineering, psychiatry and behavioural sciences at Stanford University in the US. Hegemann, a German biophysicist, conducted pioneering research into light-sensitive proteins found in microorganisms, while Nagel, a German neuroscientist, contributed to the discovery and characterisation of microbial opsins and demonstrated their ability to work as light-controlled ion channels.
Together, their work has given scientists an unprecedented tool for exploring how the brain’s complex networks produce memories, emotions and behaviour.
(With IANS inputs)
