Optogenetics allows scientists to switch the activity of individual nerve cells on or off in a living brain using light.

STOCKHOLM: American scientist Karl Deisseroth and German researchers Peter Hegemann and Georg Nagel have won the 2026 Nobel Prize in Physiology or Medicine for discoveries that transformed scientists’ understanding of how light can control nerve cells and how the brain functions.

The Nobel Assembly at Sweden’s Karolinska Institutet announced that Deisseroth, 54, Hegemann, 71, and Nagel, 73, were awarded the prize for their “discoveries concerning light-gated ion channels and optogenetics.”

Optogenetics Opens New Window Into the Brain

Optogenetics allows scientists to switch the activity of individual nerve cells on or off in a living brain using light.

Thomas Perlmann, Secretary-General of the Nobel Assembly at Karolinska Institutet, said the technique is now being used by laboratories around the world to investigate the brain’s complex functions.

The discovery has also opened potential medical applications. Researchers are conducting clinical trials aimed at restoring vision in people affected by retinitis pigmentosa by introducing light-sensitive proteins into the retina.

Scientists are also exploring whether optogenetics could improve cochlear implants by enabling more precise stimulation of the auditory nerve than conventional electrical devices.

The three laureates will share a prize of 12 million Swedish kronor, equivalent to about $1.2 million.

Discoveries Behind the Nobel Prize

The research that led to the breakthrough began in the early 1990s, when Hegemann studied how the single-celled alga Chlamydomonas responds to light within fractions of a second.

He proposed that a specific protein could detect light and function as an ion channel.

Nagel later tested the theory by introducing Chlamydomonas genes into frog eggs. His experiments led to the discovery of channelrhodopsin-2, a light-sensitive ion channel that opens when exposed to light.

In 2003, Hegemann and Nagel demonstrated that the protein could be introduced into human and hamster cells, allowing light to trigger electrical impulses.

Deisseroth subsequently demonstrated in 2005 that the technique could be used to control nerve cells in living rats. The approach was named optogenetics the following year.

Laureates ‘Surprised and Delighted’

Perlmann said he had spoken with all three laureates shortly after the announcement and described them as surprised and delighted by the recognition.

According to Perlmann, all three researchers expressed happiness at receiving the prize alongside one another and described each other as friends.

The medicine prize traditionally marks the beginning of the annual Nobel Prize announcements. Prizes in physics, chemistry, literature, peace and economics will follow in the coming days.

Nobel Prize Tradition

The original five Nobel Prizes were established through the will of Swedish inventor and industrialist Alfred Nobel and have been awarded since 1901, with only limited interruptions, mainly during the two World Wars.

The economics prize was added in 1968 by Sweden’s central bank, the Riksbank.

The Nobel Prize in Physiology or Medicine has recognised several landmark scientific discoveries, including Alexander Fleming’s discovery of penicillin and Karl Landsteiner’s identification of human blood groups.

Last year, American scientists Mary Brunkow and Fred Ramsdell, along with Japan’s Shimon Sakaguchi, received the medicine prize for research explaining how the immune system prevents attacks on healthy cells, opening possibilities for new treatments for diseases including cancer.

Nobel laureates are selected by expert committees appointed by the institutions responsible for awarding the prizes.

The awards are presented in Stockholm, except for the Nobel Peace Prize, which is presented in Oslo.

The annual Nobel celebrations culminate on December 10, the anniversary of Alfred Nobel’s death. Laureates receive their awards at ceremonies attended by the royal families of Sweden and Norway before being honoured at traditional gala banquets.