Let there be light: On the 2026 Nobel Prize in Physiology/Medicine

The first of the Nobel announcements has come, heralding the season of celebrating the fruits of the perennial human endeavour to know more and use that knowledge to benefit people. The 2026 Nobel Prize in Physiology or Medicine went jointly to Karl Deisseroth, Peter Hegeman and Georg Nagel “for their discoveries concerning light-gated ion channels and optogenetics”. True to Alfred Bernhard Nobel’s aim of annually recognising those who have “conferred the greatest benefit to humankind”, this year’s Nobel went to people who shone a light, literally, on the brain, providing a quantum leap in understanding how it functions. In essence, if the brain is a puppeteer pulling the strings, the body is the marionette. The dexterity of the puppeteer is obvious, but her methods, often not. It is this that the Nobel trio sought to explain with optogenetics — making it possible to show how nerve cells communicate with each other, and the body, regulating memory, emotions and bodily functions. It allowed mapping the brain in ways that were previously impossible. As most often in work that the Nobel acknowledges and honours, there was rich collaboration across continents in advancing optogenetics. Peter Hegemann wondered what enabled Chlamydomonas, a single-celled alga, to swim towards a light source; Georg Nagel went on to discover an algal protein that can be illuminated with blue light to open a channel within, allowing charged ions to flow into the cell and create electrical impulses. Karl Deisseroth transformed the protein into a light-controlled switch for nerve cells. Practically, today, scientists use harmless viral agents to deliver genes for light-sensitive proteins into specific target cells. Then they deliver precise pulses of light, activating the channels, allowing research to study the patterns. In the decades since the laureates described their work, researchers have gone on to use optogenetics to reveal neural circuits governing specific memories, feelings and behaviours relevant to neurological and psychiatric disorders. It laid the groundwork for clinical treatments targeting conditions including Alzheimer’s and addiction. Researchers are even using the method in attempts to restore sight.

As technology facilitates easier pathways to translating scientific research that happens in labs into practical therapies, diagnostics and health-care practices that could ameliorate human health or protect it from illness, it is also important for nations to find ways to ensure that the fruits of such research actually reach all the people who might benefit from it, irrespective of their location or station in life.