Three scientists have been awarded the 2026 Nobel Prize in Physiology or Medicine for a breakthrough technology that converts algal proteins into a "switch" for nerve cells, a discovery set to usher in a new era of neuroscience.

On October 5 local time, the Karolinska Institute in Sweden announced that the 2026 Nobel Prize in Physiology or Medicine would be awarded to American scientist Karl Deisseroth and German scientists Peter Hegemann and Georg Nagel in recognition of their discoveries concerning light-gated ion channels and optogenetics.

The three will share the prize money of 12 million Swedish kronor. Per Svenningsson, chairman of the Nobel Committee for Physiology or Medicine, stated:

Optogenetics has provided a way to map the brain that we could previously only dream of.

As has been said, the contributions of these scientists herald the arrival of a new era in neuroscience. Optogenetics technology enables scientists to precisely switch individual nerve cells on and off within the living brain, thereby revealing how neural circuits shape memory, emotion, and behavior.

At present, the method has been widely applied in laboratories around the world and has been attempted in clinical settings to restore vision in visually impaired patients.

From Algae to the Brain: The Origins of a Discovery

The starting point of this research stemmed from Peter Hegemann's curiosity about a seemingly simple question: how does the single-celled alga Chlamydomonas sense a light source and swim toward it?

Peter Hegemann began his research driven by this curiosity. In the early 21st century, together with Georg Nagel, he discovered an algal protein called channelrhodopsin, which is distributed on the cell surface.

When exposed to blue light, the channel inside the protein opens immediately, and charged ions rush into the cell, generating an electrical signal. More critically, the two found that no matter which type of cell this protein was introduced into, that cell would become sensitive to light.

In 2003, a team led by Nagel, Hegemann, and Professor Ernst Bamberg further confirmed that channelrhodopsin-2 (ChR2) expressed in animal cells could indeed regulate the entry and exit of ions under the action of light, and noted in their paper that the technology could become "a powerful tool."

Hegemann is currently affiliated with Humboldt University of Berlin in Germany, and his prize-winning discoveries were made at the Max Planck Institute of Biochemistry in Martinsried, Germany. Nagel is currently a professor of molecular plant physiology at the University of W眉rzburg in Germany, and the related discoveries were made at the Max Planck Institute of Biophysics in Frankfurt. The two were born in 1954 and 1953, respectively.

Deisseroth's Key Transformation: From Protein to Neural Switch

The person who pushed this basic discovery toward practical application was American scientist Karl Deisseroth.

After reading the aforementioned paper, Karl Deisseroth, then a postdoctoral fellow at Stanford University, and doctoral student Edward Boyden quickly established a collaboration with Nagel's team to introduce ChR2 into neurons.

Deisseroth solved the core challenge of stably expressing ChR2 on the neuronal cell membrane, while Boyden developed a fiber-optic system capable of precisely controlling light.

At 1 a.m. on August 4, 2004, Boyden applied blue light stimulation to neurons expressing ChR2 under a microscope, and the first tested neuron immediately generated a stable action potential within milliseconds. That night, the prototype of modern optogenetics technology was declared born.

He published this breakthrough result in 2005. Two years later, he further achieved the goal of controlling nerve cells with light in the brains of living mice, marking the formal entry of optogenetics technology into the experimental application stage.

Deisseroth was born in 1971 and obtained his Ph.D. and M.D. from Stanford University in the United States in 1998 and 2000, respectively. He currently holds the D.H. Chen Professorship at the Howard Hughes Medical Institute and Stanford University, with research spanning bioengineering, psychiatry, and behavioral sciences.

Clinical Prospects and a New Era in Neuroscience

Since then, the field of optogenetics has shown explosive development. Moreover, the significance of optogenetics has extended beyond basic research and is now reaching into clinical medicine:

In December 2005, a joint team led by Nagel and Professor Alexander Gottschalk used optogenetics for the first time to alter the behavior of nematodes;

In 2006, Professor Pan Zhuohua's research group enabled mice with retinal disease to regain light responses;

In 2007, Professor Feng Guoping's research group reported a transgenic mouse system stably expressing ChR2-YFP.

With this technology, researchers have been able to reveal the neural circuits behind specific memories, emotions, and behaviors associated with neurological and psychiatric disorders. At the clinical level, researchers are attempting to use this method to restore visual function in patients with impaired vision.

The term "optogenetics" itself did not first appear in academic papers until 2006, but related research has rapidly swept through laboratories worldwide.

The Karolinska Institute noted in its announcement that optogenetics "has fundamentally changed our understanding of the brain," with new discoveries emerging every day to help humanity unravel the ultimate mystery of how the brain works. The Nobel Committee characterized the contributions of the three laureates as "laying the foundation for a new era in neuroscience."

The award ceremony will be held in Stockholm on December 10, as is customary.