German duo, US scientist win Nobel Medicine Prize for brain research

The Nobel Prize in Physiology or Medicine has been awarded to German duo Peter Hegemann and Georg Nagel and US scientist Karl Deisseroth for their discoveries in the field of optogenetics.

The Nobel Assembly at the Karolinska Institute in Stockholm announced the prize, seen as the most prestigious award for medical scientists, on Monday.

"The laureates have laid the foundation of a new era in neuroscience," the institute stated. 

The field of optogenetics is a "method that makes it possible to show how nerve cells shape memories, feelings and behaviours in the living brain," the institute added.

Hegemann is based at the Humboldt University of Berlin, while Nagel is at the University of Würzburg, also in Germany. Deisseroth teaches at Stanford University in the United States, while he is also a member of the Howard Hughes Medical Institute.

The Nobel Foundation recently increased its award money to 12 million Swedish kronor (€1.07 million) as the institute celebrates the 125th anniversary of the prizes. 

Helping to understand the brain

The 2026 Nobel Prize in Physiology or Medicine recognizes the leading lights of the field of optogenetics, which "provides opportunities for mapping the brain in a way that we could once only dream of," said Per Svenningsson, chair of the Nobel Committee for Physiology or Medicine.

The field has "fundamentally altered our understanding of the brain," the institute explained. 

"Peter Hegemann and Georg Nagel discovered a remarkable protein, channelrhodopsin, in a single-celled alga. Karl Deisseroth transformed the protein into a light-controlled switch for nerve cells."

The technology has "rapidly gained global impact," allowing researches to "reveal neural circuits governing specific memories, feelings, and behaviours relevant for neurological and psychiatric disorders." 

It has also had specific applications in clinical medicine, with researchers "using the method in attempts to restore sight in people with visual impairment."

"Every day brings new discoveries, helping to solve one of humanity’s great mysteries: how our incredible brain works," the institute concluded.

Deisseroth: Tremendous honour

It was a sleepless night for Karl Deisseroth, who told dpa he was "settling down for bed" due to the time difference when the call came from Stockholm. 

"It's incredibly surprising and gratifying," said the 54-year-old. "It's a tremendous honour."

Deisseroth said he and his collaborators "had to solve so many things to make optogenetics work," describing "major challenges that had to be overcome."

"But we stuck with it," he added.

Hegemann told the Tagesspiegel newspaper after the announcement that "nobody was interested in what we were initially researching on green algae - hardly anyone took it seriously." 

Last year, the Nobel Prize in Physiology or Medicine was awarded to US duo Mary Brunkow and Fred Ramsdell and Japan's Shimon Sakaguchi. They were honoured for their discoveries concerning peripheral immune tolerance, which prevents the immune system from harming the body. 

Nobel season

Prior to this year's award, a total of 232 people have received the Nobel Prize in Physiology or Medicine since 1901, including 14 women. 

The first prize was awarded to the German bacteriologist Emil Adolf von Behring for the discovery of a treatment for diphtheria.

The Nobel season continues on Tuesday and Wednesday, when the winners of the Physics and Chemistry Prizes will be announced. 

These will be followed by the Literature and Peace Prizes on Thursday and Friday, before the announcements conclude next Monday with the Nobel Prize in Economics, funded by the Swedish Central Bank.

In keeping with tradition, the formal presentation of all the prizes takes place on December 10, the anniversary of the death of the prize's founder, Alfred Nobel.