Deisseroth, Hegemann and Nagel jointly won the 2026 Nobel Prize in Medicine.
Their discoveries enabled scientists to control selected nerve cells using light.
Hegemann and Nagel discovered channelrhodopsin; Deisseroth demonstrated its use in living brains.
Karl Deisseroth, Peter Hegemann and Georg Nagel have jointly won the 2026 Nobel Prize in Physiology or Medicine for discoveries that enabled scientists to control nerve-cell activity with light.
Announcing the award on Monday, October 5, the Nobel Assembly at Karolinska Institutet recognised the researchers “for their discoveries concerning light-gated ion channels and optogenetics”.
Deisseroth, a 54-year-old American, and German scientists Hegemann, 71, and Nagel, 73, will share the prize of 12 million Swedish kronor, approximately $1.2 million.
Their work gave researchers a way to study how individual nerve cells contribute to the functioning of the brain. Optogenetics “makes it possible to switch on, or off, the activity of individual nerve cells in a living brain”, the prize-givers said.
“This method is now being used in laboratories around the world to reveal the brain’s mysteries.”
What Is Optogenetics, And How Does It Work?
Neurons communicate through electrical signals that support functions such as movement, memory, vision and the experience of pain. Optogenetics allows researchers to influence those signals by making selected cells sensitive to light.
Hegemann and Nagel discovered channelrhodopsin, a light-sensitive protein. They found that introducing it into different cells made those cells respond to illumination.
Deisseroth then introduced the gene for channelrhodopsin into rat nerve cells. Shining blue light on the modified cells triggered a nerve signal. He subsequently made the technique work in the brains of living mice.
The method combines genetic modification with light: researchers place genes for light-sensitive proteins in particular cells, then use illumination to activate or suppress their activity. By controlling selected neurons, scientists can investigate the roles they play within complex brain circuits.
The medicine prize opens this year’s Nobel announcement week. The physics award is scheduled for October 6, followed by chemistry, literature and peace. The Sveriges Riksbank Prize in Economic Sciences will be announced on October 12.
Last year’s medicine laureates were US scientists Mary E. Brunkow and Fred Ramsdell and Japan’s Shimon Sakaguchi, recognised for their discovery of regulatory T cells. Their research helped open avenues for treating cancer and autoimmune diseases, in which the immune system attacks healthy cells.
The awards will be presented on December 10, the anniversary of Alfred Nobel’s death. The Swedish inventor established the prizes through his will to honour those who had conferred the greatest benefit on humankind.
