The 2026 Nobel Prize in Physiology or Medicine honoured optogenetics, a technology that lets scientists control brain cells with flashes of light.

The method works by inserting genes for light-sensitive proteins into specific neurons. When researchers shine light of a particular colour, those neurons switch on or off. The proteins come from algae and other microbes that naturally respond to light.

Optogenetics has changed brain research. Scientists can now test exactly which brain circuits control movement, memory, mood and sleep. The precision is far greater than older methods such as electrodes or drugs.

The technique is also guiding future treatments. Researchers are testing light-based therapies for blindness, Parkinson’s disease and depression. Human trials remain early, but animal studies show strong promise. The 2026 prize recognised work that began in the early 2000s, when scientists first showed that light-sensitive proteins could switch neurons on and off in living animals.

Context: optogenetics grew from work in the early 2000s and is now a standard tool in neuroscience labs worldwide.