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Karl Deisseroth, Peter Hegemann and Georg Nagel are shown on the screen as they are awarded the 2026 Nobel Prize in Physiology or Medicine.Pontus Lundahl/The Associated Press
A discovery that began with algae and turned into a powerful method for investigating the brain is the subject of this year’s Nobel Prize in Physiology or Medicine.
On Monday, the Nobel Assembly at the Karolinska Institute in Sweden announced this year’s prize has been has awarded to three scientists, one in the United States and two in Germany, for work leading to the development of the field known as optogenetics.
Karl Deisseroth of Stanford University, Peter Hegemann of Humboldt University of Berlin and Georg Nagel of the University of Würzburg will share equally in the prize, worth approximately $1.7-million dollars.
The story of this year’s medical Nobel begins in the 1980s, when Dr. Hegemann, a biophysicist, was working at the Max Planck Institute of Biochemistry in Martinsried and became fascinated with the ability of pond algae to sense and respond to sunlight. Algae rise or sink depending on the amount of light they are exposed to. By doing so they can regulate photosynthesis.
The phenomenon led to the discovery of a class of proteins called channelrhodopsins, which the algae use to turn light into electrical signals. Dr. Hegemann found the underlying gene associated with channelrhodopsin in algae, which Dr. Nagel was then able to produce in frog egg cells to study the protein’s function.
“Nagel and Hegemann realized exactly what they had found. They had just discovered the switch neuroscientists had long dreamed of,” said Abdel El Manira, a member of the Nobel Committee, during Monday’s announcement.
The practical value of the discovery was realized in 2005, when Dr. Deisseroth and Ed Boyden, then a postdoctoral researcher in Dr. Deisseroth’s lab at Stanford, showed how a channelrhodopsin gene obtained from Dr. Nagel could be inserted into the DNA of a rat neuron. This effectively created brain cells that could be switched on or off with exposure to light. With that innovation, optogenetics was born.
Researchers have now used the technique to activate individual cells within networks of neurons to understand how brains are wired. The method has opened a new window onto a range of complex neural functions including perception, memory and emotion.
In recent years the tool has been extended beyond neuroscience to develop therapies for retinitis pigmentosa, cancer and diabetes that harness light to activate cells.
Over the years, the advancements made possible by optogenetics have been widely celebrated. In 2016, Dr. Deisseroth and Dr. Boyden, now at the Massachusetts Institute of Technology, received the Breakthrough Prize in Life Sciences for their contributions.
In 2018, Dr. Deisseroth, Dr. Boyden and Dr. Hegemann were among the winners of the Canada Gairdner International Award.
In an interview with The Globe and Mail that year, Dr. Hegemann said the unlikely combinations of knowledge from areas like aquatic biology and neuroscience is “the beauty and the stimulating factor in science” that can lead to unexpected advancements.
“This is how the big jumps are produced,” he said.
Monday’s announcement kicks off a week of Nobel prize reveals, with the recipient or recipients of the physics prize to be named on Tuesday, chemistry on Wednesday, literature on Thursday and the Nobel Peace Prize on Friday.
The prizes were first awarded in 1901, with categories stipulated in the will of Swedish businessman and inventor, Alfred Nobel.
A sixth prize for economics, added in 1969, is set to be announced on Oct. 12.
All the prizes are bestowed annually at a special ceremony held in Stockholm on Dec. 10, the anniversary of Alfred Nobel’s death in 1896.