German and U.S. scientists win Nobel medicine prize for work on optogenetics

German and U.S. scientists Karl Deisseroth, Peter Hegemann and Georg Nagel have won the 2026 Nobel Prize in Physiology or Medicine for their work on light-gated ion channels and optogenetics. The Nobel Assembly at Sweden's Karolinska Institute announced the award on Monday, citing the laureates' contributions to understanding how the brain functions through the use of light to control nerve cell activity. Thomas Perlmann, Secretary-General of the Nobel Assembly at Karolinska Institutet, stated that the winners were selected for their "discoveries concerning light-gated ion channels and optogenetics." According to Perlmann, optogenetics allows researchers to activate or deactivate individual nerve cells in a living brain. This technique is currently being used globally to explore the complexities of the brain. In clinical settings, researchers are applying optogenetics to restore vision in individuals affected by retinitis pigmentosa, a condition that causes blindness. They insert a light-sensitive protein into the retina to help regain sight. Additionally, scientists are exploring its potential to enhance cochlear implants, offering more precise stimulation of the auditory nerve compared to existing electrical devices. The Nobel Prize in Physiology or Medicine typically marks the beginning of the annual Nobel announcements, followed by awards in physics, chemistry, literature, peace and economics over the following days. Deisseroth, Hegemann and Nagel will share a total prize sum of 12 million Swedish crowns, equivalent to $1.2 million. Hegemann began investigating the alga Chlamydomonas in the early 1990s, studying how it reacts to light within half a millisecond. He proposed that a single protein captures light and acts as an ion channel. Nagel tested this hypothesis by injecting Chlamydomonas genes into frog eggs, leading to the discovery of channelrhodopsin-2, a protein that opens when exposed to light. In 2003, they published findings showing that this protein can be introduced into human and hamster cells to generate electrical impulses using light. By 2005, Deisseroth at Stanford University demonstrated the technique in rat nerve cells, and the method was subsequently named optogenetics. Perlmann mentioned that he spoke with each laureate earlier in the day and noted their surprise and delight at receiving the prize. All three expressed that they considered it an honor to be awarded alongside the others, referring to one another as friends. The Nobel Prizes have been awarded annually since 1901, with only minor interruptions during World War I and World War II. A sixth prize, the Economics Prize, was established in 1968 by Sweden's central bank, the Riksbank. The Nobel Prize in Physiology or Medicine has recognized several groundbreaking scientific achievements, including Alexander Fleming's discovery of penicillin in 1945 and Karl Landsteiner's identification of human blood groups in 1930. Last year, the prize was awarded to Mary Brunkow, Fred Ramsdell and Shimon Sakaguchi for their work on the immune system's ability to spare healthy cells, potentially opening new treatment avenues for diseases like cancer. Nobel laureates are selected by expert committees appointed by the respective prize-awarding institutions. The awards are presented in Stockholm, except for the Peace Prize, which is given in Oslo. These traditions continue more than 125 years after Alfred Nobel signed his will. The Nobel celebrations conclude on December 10, the anniversary of Nobel's death, when laureates attend ceremonies in Stockholm and Oslo, hosted by the royal families of Sweden and Norway, and participate in gala banquets in their honor.