The American professor Karl Deisseroth has been named one of the three winners of the Nobel Prize in Physiology or Medicine. In 2021, Deisseroth was awarded an honorary doctorate by Erasmus MC for his groundbreaking brain research. He is regarded as the founder of optogenetics, a technique that makes it possible to activate specific brain cells using light.
On Monday 5 October 2026, the Nobel Committee in Stockholm awarded the prize to the American Karl Deisseroth and the Germans Peter Hegemann and Georg Nagel "for their discoveries concerning light-activated ion channels and optogenetics". This method reveals how nerve cells shape memories, emotions and behaviour in the brain.
Karl Deisseroth graduated from Harvard, obtained his PhD at Stanford where he also obtained his medical degree. At the same university, he is now Professor of Bioengineering and of Psychiatry and Behavioural Sciences. The honorary doctor is also a researcher at the Howard Hughes Medical Institute. Deisseroth is board-certified by the American Board of Psychiatry and Neurology and is still a practising psychiatrist specialising in affective disorders and autism spectrum diseases.
Most prominent neurobiologist
Honorary supervisor Chris de Zeeuw, Professor of Neuroscience at Erasmus MC and former Deputy Director of the Brain Institute of the Royal Netherlands Academy of Arts and Sciences (KNAW), described Deisseroth in 2021 as the most prominent neurobiologist of the past ten years due to his key role in optogenetics, a field in which he is regarded as the founder. By inserting proteins into brain cells, this technique makes it possible to activate or inhibit certain brain cells very specifically, both in time and space. De Zeeuw: 'There is now hardly any neuroscience lab in the world that does not use this technique; that shows how important his work is.'
De Zeeuw emphasises that the development of optogenetics goes far beyond simply being a new research technique. 'In a sense, Karl was following a statement by Sydney Brenner, who won the Nobel Prize in Physiology or Medicine in 2002: "Progress in science depends on new techniques, new discoveries and new ideas, probably in that order."' Before the advent of optogenetics, researchers were unable to switch nerve cells on or off in such a targeted manner. 'Karl solved that problem in a single stroke. Since then, we have discovered many new things about how the brain works, from memory and emotions to decision-making. Moreover, we can now start to design therapies for many related brain disorders. That really highlights just how important his work has been.'
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