Nobel Prize in Peace
The bus driver's daughter who became a judge
Law firms in apartheid South Africa wouldn't hire Navi Pillay. So in 1967 she opened her own.
2:24 filmHome › This week's edition
This week's edition · Nobel Prize in Medicine
A light switch for brain cells
A pond alga's tiny door that opens in light, put into nerve cells. A tool for understanding the brain, not a cure.
The film plays from YouTube. Open on YouTube
Shine a blue light into one side of a mouse's brain, and the mouse turns left. It started with a tiny green speck of pond life, and this week it won the 2026 Nobel Prize in Physiology or Medicine for Peter Hegemann, Georg Nagel and Karl Deisseroth.
A single-celled alga that reacts to light in half a thousandth of a second. Years of setbacks. A light-opened "door" found in frog eggs. A Stanford psychiatrist who was turned down for funding. A paper rejected by Nature and Science without review. Then a thin optical fiber, and a light switch for brain cells. Today it helps scientists map circuits for movement, sleep and waking.
How we made thisArchive footage and photographs, checked against the original sources. Full credits are listed with the film on YouTube.
The weekly email
