Overview
- The Nobel Assembly at the Karolinska Institute awarded the 2026 Physiology or Medicine prize to Karl Deisseroth, Peter Hegemann and Georg Nagel, an announcement made on Monday that the three will share the 12 million SEK prize.
- Hegemann and Nagel identified light‑sensitive proteins called channelrhodopsins in the alga Chlamydomonas and showed those proteins are light‑gated ion channels.
- Deisseroth adapted channelrhodopsin‑2 for use in mammalian neurons, creating the optogenetic ‘light switch’ that lets researchers turn chosen cells on or off with light.
- Optogenetics combines genetic targeting and light delivery to control neurons with millisecond precision, which lets scientists test causal links between specific cells and behaviors such as memory, fear or movement.
- The prize highlights vast lab use of the method and growing clinical research for retinal restoration, but translation to routine brain therapies remains experimental because of delivery, immune response and deep‑tissue light‑access challenges.