2026 Nobel Medicine Prize: 3 scientists honoured for discoveries that control cells with light

Karl Deisseroth, Peter Hegemann and Georg Nagel have been awarded the 2026 Nobel Prize in Physiology or Medicine for their pioneering discoveries involving light-gated ion channels and optogenetics.

The Nobel Assembly at Sweden's Karolinska Institute announced the three laureates on Monday, recognising research that has given scientists a way to control the activity of individual cells using light. Their work has become an important tool in neuroscience, allowing researchers to study how nerve cells communicate and how the brain functions.

“Optogenetics makes it possible to switch on, or off, the activity of individual nerve cells in a living brain. This method is now being used in laboratories around the world to reveal the brain’s mysteries”, the Nobel Assembly said.

How their discovery changed neuroscience

Hegemann, 71, and Nagel, 73, both German scientists, made a key breakthrough by discovering channelrhodopsin, a protein with unusual light-sensitive properties.

They found that introducing the protein into different types of cells could make those cells respond to light. The discovery provided the foundation for a new way of controlling cellular activity without relying on conventional electrical or chemical methods.

Deisseroth, 54, an American scientist, took the work further by introducing the gene responsible for channelrhodopsin into nerve cells taken from rats. When the cells were exposed to blue light, he was able to trigger a nerve signal.

He later demonstrated that the technique could be used inside the brains of living mice, showing that light could act as a precise switch for controlling nerve-cell activity.

Prize shared by three scientists

The three laureates will share a prize of 12 million Swedish crowns, equivalent to around $1.2 million, according to Reuters.

Their work has since helped researchers investigate the brain at the level of individual nerve cells. Optogenetics allows scientists to activate or silence selected neurons and observe what happens, offering a powerful way to examine the links between brain activity and behaviour.

Who selects the medicine Nobel laureates?

The Nobel Prize in Physiology or Medicine is awarded by the Nobel Assembly at Karolinska Institutet. The assembly has 50 voting members, made up of professors in medical subjects at the Stockholm-based institute.

Its Nobel Committee, whose members are elected from among the assembly for three-year terms, carries out the work involved in selecting the laureates.

Last year, the medicine Nobel was awarded jointly to Mary E. Brunkow, Frederick J. Ramsdell and Shimon Sakaguchi for their discoveries concerning peripheral immune tolerance.