2026 Nobel Prize in Medicine: optogenetics, the method that controls nerve cells with light

On 5 October 2026, the Nobel Assembly at Karolinska Institutet announced the laureates of the Nobel Prize in Physiology or Medicine: Karl Deisseroth (Howard Hughes Medical Institute and Stanford University, USA), Peter Hegemann (Humboldt University of Berlin, Germany) and Georg Nagel (University of Würzburg, Germany). The prize was awarded “for their discoveries concerning light-gated ion channels and optogenetics”.

From an alga to the brain

It started with a question: how can the single-celled alga Chlamydomonas react to light so quickly? In the early 1990s, Peter Hegemann, at the Max Planck Institute for Biochemistry in Martinsried, proposed that a single protein might both capture light and act as an ion channel.

Together with Georg Nagel, at the Max Planck Institute for Biophysics in Frankfurt, he confirmed the idea in the early 2000s. The proteins, named channelrhodopsin-1 and channelrhodopsin-2, open when illuminated and let ions through, creating an electrical signal. When placed in other cells, including human cells, they made those cells sensitive to light.

Karl Deisseroth, at Stanford, introduced the channelrhodopsin-2 gene into rat nerve cells grown in the laboratory and, in 2005, showed that blue light triggered nerve signals. In 2007 his team achieved the same in the brains of living mice. The method became known as optogenetics.

Why it matters

Optogenetics lets researchers switch specific types of nerve cells on or off and see what they do. This has revealed circuits involved in pain, thirst, reward, attention and memory. According to the Nobel Committee, the method has improved understanding of conditions such as depression, anxiety, schizophrenia, Alzheimer’s disease and Parkinson’s disease.

What it means for patients now

Optogenetics is first and foremost a research tool. Its use as a treatment is only taking its first steps, in clinical trials. In people who lost their sight to retinitis pigmentosa, researchers place a channelrhodopsin-like protein in the retina. In a case published in Nature Medicine in 2021, a patient wearing special light-emitting goggles was able to perceive, locate and touch objects. A possible use in cochlear implants is also being explored.

Long-term safety and effectiveness are not yet known, nor how many patients could benefit. If you have a retinal or neurological condition, discuss available clinical trials with your doctor.