Three Scientists Honoured For Breakthrough In Neuroscience

The 2026 Nobel Prize in Physiology or Medicine has been awarded to American scientist Karl Deisseroth and German researchers 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 the Karolinska Institutet announced the laureates on Monday, recognising their work in developing a method that enables scientists to control and study nerve cells using light.

The Nobel Committee said their discoveries had “laid the foundation for a new era in neuroscience” by enabling researchers to study neural circuits responsible for specific memories, feelings and behaviours associated with neurological and psychiatric disorders.

Hegemann and Nagel discovered channelrhodopsin, a light-sensitive protein that functions as an ion channel. Deisseroth later transformed the discovery into a light-controlled switch for nerve cells, helping establish what became known as optogenetics.

The technique combines optics and genetics to enable researchers to switch individual nerve cells on or off in a living brain.

Thomas Perlmann, secretary-general of the Nobel Assembly at Karolinska Institutet, said optogenetics had opened new possibilities for understanding the brain.

“Optogenetics makes it possible to switch on, or off, the activity of individual nerve cells in a living brain,” Perlmann said.

“This method is now being used in laboratories around the world to reveal the brain’s mysteries.”

The Nobel Committee said optogenetics had fundamentally altered scientists’ understanding of how the brain functions, while also providing insights into how neural circuits become disrupted in neurological and psychiatric conditions.

Abdel El Manira, a Nobel Committee member and professor of neuroscience, said the technique’s impact extended beyond research into the healthy brain.

“The impact of optogenetics extends far beyond understanding the healthy brain. It has also helped reveal how brain circuits are disrupted, with implications for conditions such as blindness, depression, addiction and dementia,” he said.

How The Discovery Works

Hegemann began investigating in the early 1990s how the single-celled green alga Chlamydomonas responds to light.

He hypothesised that a single protein was responsible for detecting light and acting as an ion channel. Nagel subsequently tested the theory by introducing genes from Chlamydomonas into frog eggs, leading to the discovery of channelrhodopsin-2, an ion channel that opens when exposed to light.

In 2003, Hegemann and Nagel demonstrated that the protein could be introduced into human and hamster cells, allowing light to generate electrical impulses.

Deisseroth, a professor of bioengineering and psychiatry and behavioural sciences at Stanford University, later demonstrated in 2005 that the technique could be used in rat nerve cells. The approach was subsequently named optogenetics in 2006.

The breakthrough has since enabled researchers to study specific neural circuits with unprecedented precision, including those associated with memory, behaviour and emotions.

The technique is also being investigated for potential medical applications. Researchers are conducting clinical trials aimed at restoring vision in people blinded by retinitis pigmentosa by introducing light-sensitive proteins into the retina.

Scientists are also exploring whether optogenetics could improve cochlear implants by enabling more precise stimulation of the auditory nerve than conventional electrical devices.

Researchers hope the technology could eventually contribute to treatments for neurological disorders, including Parkinson’s disease and epilepsy.

[Karl Deisseroth, Peter Hegemann and Georg Nagel are awarded the 2026 Nobel Prize in Physiology or Medicine, as announced during a press conference at the Nobel Forum at Karolinska Institutet in Stockholm, Sweden, October 5, 2026. TT News Agency/Pontus Lundahl/via REUTERS]

Who Are The Nobel Laureates?

Hegemann, 71, is a professor of neuroscience at Humboldt University of Berlin and is regarded as a leading expert in photobiology and one of the pioneers of optogenetics.

Nagel, 73, is a biophysicist and professor of neurophysiology at the University of Würzburg in Germany.

Deisseroth, 54, is a professor of bioengineering and psychiatry and behavioural sciences at Stanford University in the United States.

The Nobel Assembly said the three scientists were surprised and delighted by the recognition.

Perlmann said he had spoken with all three laureates shortly after the announcement.

“All three said the same thing, that they thought it was absolutely wonderful to receive the prize with the other two and they call them my friends. That it’s such an honour to receive them together. So that’s something they conveyed,” he said.

The laureates will share the Nobel Prize award of 12 million Swedish kronor, equivalent to about $1.2 million.

The Medicine prize is the first of the 2026 Nobel awards to be announced. The prizes in Physics, Chemistry, Literature and Peace will be announced later in the week, while the awards will be presented at ceremonies in Stockholm, Sweden, on December 10.