Three scientists win 2026 Nobel Prize in medicine, sciencenews.org reports

Three scientists shared the 2026 Nobel Prize in physiology or medicine for developing optogenetics, a technology that uses light to precisely activate specific cells and observe behavioral changes, sciencenews.org reported. Key contributors Peter Hegemann, Georg Nagel, and Karl Deisseroth were honored for foundational work that transformed neuroscience by letting researchers link neural circuits directly to specific behaviors.

The human brain contains a galaxy of nearly 90 billion neurons communicating through some 100 trillion connections. Neuroscientists long dreamed of a neuronal switch to turn specific neurons on or off with great precision, according to Karolinska Institute neuroscientist Abdel El Manira during the Nobel Assembly announcement.

From Algae to Neural Circuits

The prize-winning research began in the early 2000s with the study of an eye spot in a single-celled green alga called Chlamydomonas. Hegemann, working at the Max Planck Institute for Biochemistry, and Nagel, at the Max Planck Institute for Biophysics, discovered a unique protein in the alga’s eye spot that generated an electrical impulse when illuminated, enabling the organism to move.

Building on that discovery, Stanford University neuroscientist Karl Deisseroth tested whether channelrhodopsin could activate brain cells. Deisseroth and colleagues inserted the gene for channelrhodopsin into rat nerve cells in culture, finding they reacted to light instantaneously. Beaming blue light through the fibers allowed the researchers to control the movements of the rodents’ whiskers.

Optogenetics Helps Reveal How Brain Circuits Are Disrupted

The resulting technology, known as optogenetics, gave researchers a direct tool to test links between brain circuits and behaviors. El Manira stated that the technology transformed neuroscience and helped reveal how brain circuits are disrupted, which carries implications for conditions including blindness, depression, and dementia.

More on this story: 2026 Nobel Prize in Medicine Awarded for Breakthroughs in Optogenetics