What is optogenetics, for which the Nobel Prize in Medicine has been awarded?

The Nobel Prize in Physiology or Medicine 2026 is awarded for optogenetics, a method that makes it possible to show how nerve cells shape memories, feelings and behaviours in the living brain. Peter Hegemann and Georg Nagel discovered a remarkable protein, channelrhodopsin, in a single-celled alga. Karl Deisseroth transformed the protein into a light-controlled switch for nerve cells.