Everything you need to know about the 2026 Nobel Prize in Medicine

In 2026, the Nobel Prize in Physiology or Medicine went to Karl Deisseroth, Peter Hegemann and Georg Nagel for optogenetics: a way to switch specific brain cells on and off with light. It started with a tiny green alga called Chlamydomonas and a light-sensitive protein, channelrhodopsin, that works like a door in the cell's surface. Put the gene for that protein into a neuron, shine blue light on it, and the neuron fires. In this video we look at the problem it solved, how it works, what scientists did with it in mice (including switching on a fear memory with light), how it helped a blind man see objects again, why we can't just put it in your brain, and why it won the biggest prize in medicine. ⚠️ This video is for educational purposes only and is not medical advice. CHAPTERS 00:00 A light in the brain 01:22 The problem 03:34 A switch from algae 06:02 Choosing the neurons 07:46 What we did to the mice 09:39 Can we do this to humans? 10:53 Why not in your brain? 12:02 Why a Nobel Prize? 12:50 Why these three? 14:01 From pond water to a Nobel Prize