Deisseroth, Hegemann and Nagel win medicine Nobel for optogenetics

On Oct. 5, Stockholm’s Karolinska Institutet Nobel Assembly awarded the 2026 physiology or medicine prize jointly to Karl Deisseroth, Peter Hegemann and Georg Nagel. The award recognises discoveries involving light-gated ion channels and optogenetics, a method researchers use to control selected nerve cells with light and investigate how brain circuits shape memories, feelings and behaviour.¹²⁴⁶

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A light-controlled neural switch

Optogenetics combines light with genetic modification to activate or silence selected nerve cells. Using this approach, scientists can activate or suppress specific brain pathways, helping them chart neural activity and assess what distinct neuron classes do. The Nobel committee said the technology is used in laboratories around the world.¹²³

The work began with channelrhodopsin, a light-sensitive ion-channel protein discovered by Hegemann and Nagel in a single-celled alga in the early 2000s. According to Nature, the two scientists were working together at the Max Planck Institute for Biochemistry. The protein rapidly opens a channel when exposed to light, a property that became the basis of the new research tool.³⁵⁹

According to Nature, Deisseroth's team inserted the channelrhodopsin gene into rat nerve cells and showed that illumination made them send signals to neighbouring neurons. Other accounts said he developed a means of using light to control neurons in live mice. The first result from the optogenetics work was published in 2005, according to EL PAÍS.¹⁵⁹

The resulting technique gave scientists precise control over selected populations of neurons. Researchers have used light-controlled circuits in animals to evoke memories, produce feelings and prompt behaviours, while studying the neural pathways involved. Per Svenningsson, who leads the Nobel Committee for Physiology or Medicine, said optogenetics enables forms of brain mapping that had once seemed unimaginable.³⁴⁹

From laboratory tool to medical research

The Nobel Assembly said optogenetics had fundamentally changed understanding of the brain. The method has helped researchers identify circuits associated with particular memories, emotions and behaviours, including circuits relevant to neurological and psychiatric disorders. It has also allowed scientists to examine the types of neurons involved in those conditions.¹³

Potential medical applications remain under investigation. Researchers are exploring ways to restore sight and studying possible relevance to blindness, depression, addiction, dementia, Parkinson’s disease and epilepsy. MUNDIARIO reported that widespread medical use still faces technical and safety challenges and that results from animal studies do not automatically translate to humans. The dossier does not establish that optogenetics has produced an effective clinical therapy.¹⁹¹²

Deisseroth works at Stanford University in California; Hegemann is at Berlin's Humboldt University; and Nagel is affiliated with Germany's University of Würzburg. Thomas Perlmann, the medicine Nobel committee's secretary, said he spoke with each of the three winners by phone on the announcement day.²

The prize totals 12 million Swedish kronor, equivalent to just over €1 million or about $1.2 million. It opened the week of Nobel announcements, with the physics, chemistry, literature and peace prizes to follow and the Nobel Memorial Prize in Economic Sciences scheduled for Oct. 12. The medicine laureates are due to receive diplomas and gold medals from Sweden’s king at a ceremony in Stockholm on Dec. 10.¹²¹²