Karl Deisseroth

Deisseroth was born on November 18, 1971, in Boston, Massachusetts, United States.⁠[1]

From 1988 to 1992, he studied biochemical sciences at Harvard University, receiving an A.B. summa cum laude in 1992; while there he received a John Harvard Scholarship and was elected to the Phi Beta Kappa honor society.⁠[2][2]

In 1992, he entered the Medical Scientist Training Program (MSTP) at Stanford University School of Medicine, pursuing an M.D. and a Ph.D. at the same time; he received a Ph.D. in neuroscience in 1998 and an M.D. in 2000.⁠[3][2]

While studying medicine, he was originally considering becoming a neurosurgeon, but during clinical training at a psychiatric clinic he was struck by the patients’ suffering, which also led him to ask why the brain works so differently in different people. During his doctoral work he experimented with brain slices and gradually realized that to understand the diseases he encountered in the clinic, he needed to study nerve cells in the living brain.⁠[4][4][4]

From 2000 to 2004, he completed a medical internship and psychiatry residency at Stanford, receiving the National Institute of Mental Health (NIMH) Outstanding Resident Award in 2002 and certification by the American Board of Psychiatry and Neurology in 2006.⁠[2][2][2]

In 2004, he became Principal Investigator and Clinical Educator in the Department of Psychiatry at Stanford University and established his own lab, where he explored methods of controlling neural activity together with graduate students Edward Boyden and Feng Zhang.⁠[2][3]

The group tested many candidate proteins; after learning of the discovery of channelrhodopsin-2, he wrote to Georg Nagel asking for access to the DNA encoding the protein.⁠[4]

He introduced the channelrhodopsin-2 gene into rat nerve cells cultured in petri dishes, and the cells began producing the protein; when exposed to blue light, the cells immediately produced nerve signals that could be propagated to other nerve cells. In 2005, the group published the paper “Millisecond-timescale, genetically targeted optical control of neural activity” in Nature Neuroscience, with authors including Boyden, Zhang, Ernst Bamberg, Nagel, and Deisseroth, showing that pulses of light could make rat neurons expressing the algal protein fire with millisecond precision.⁠[4][4][4][5][3]

He later recalled that, of the many approaches to modulating neural activity he had explored, this was the one “with the highest risk,” but it “turned out to be the one that worked best.” That same year he became assistant professor of bioengineering and psychiatry at Stanford and received the National Institutes of Health (NIH) Director’s Pioneer Award.⁠[3][2][2]

He then began numerous collaborations, including with Hegemann and Nagel, and shared results with other researchers; with his lab at the forefront, researchers soon found more proteins sensitive to different wavelengths of light that can turn nerve cells on and off. In 2006, the method was given the name optogenetics.⁠[4][4][4]

In 2007, his group introduced the channelrhodopsin-2 gene into specific nerve cells in the motor cortex of mice and illuminated them through a thin optical fiber inserted through a small hole in the skull, controlling the movements of the mice’s whiskers and achieving light control of nerve cells in the brain of a living animal. The same year, he and collaborators used optogenetics to wake sleeping mice in a controlled manner.⁠[4][4][4]

Also in 2007, the team found halorhodopsin, derived from the archaeon Natronomonas pharaonis, which silences neurons under yellow light, allowing researchers to turn brain cells off as well as on.⁠[3]

From 2009 to 2012, he was associate professor of bioengineering and psychiatry at Stanford, and from 2009 to 2013 he was also an HHMI Early Career Investigator; in 2009 he received the Society for Neuroscience Young Investigator Award. His lab then used optogenetics to study brain disorders: working with Anatol Kreitzer of the Gladstone Institutes and others, it identified two circuits involved in Parkinsonian motor behavior and used optogenetics to reverse Parkinsonian symptoms in mice; it also identified a circuit that controls the drive for social interaction and both induced and relieved depression-like symptoms in rodents.⁠[2][2][3][3][3]

In 2012, he became full professor of bioengineering and psychiatry at Stanford University and was appointed to the D.H. Chen Professorship. The same year, he shared the Zülch Prize with Hegemann, Nagel, and Bamberg.⁠[2][5]

In 2012, working with Susumu Tonegawa, the 1987 Nobel laureate, he activated in mice a memory engram formed by a fearful experience: when these nerve cells were reactivated, the mice showed signs of fear even though there was no danger. The Nobel Committee regarded this as the first time researchers had demonstrated which nerve cells are necessary for a specific memory.⁠[4][4][4]

In 2013, he shared the Brain Prize of the Lundbeck Foundation with Gero Miesenböck, Bamberg, Boyden, Hegemann, and Nagel; from 2013 to 2019, he was also a foreign adjunct professor at the Karolinska Institutet in Sweden.⁠[5][2]

Since 2014, he has been an investigator of the Howard Hughes Medical Institute (HHMI).⁠[2][3]

In 2015, he shared the Breakthrough Prize in Life Sciences with Boyden; in 2016 he shared the Massry Prize with Hegemann and Miesenböck; and in 2017 he shared the Harvey Prize with Hegemann.⁠[5][5][5]

In 2018, he received the Kyoto Prize in Advanced Technology (Biotechnology and Medical Technology) for the discovery of optogenetics and the development of “causal systems neuroscience”; the committee held that optogenetics can activate and inhibit, with millisecond time resolution, specific neurons identified by molecular markers, moving systems neuroscience from correlational to causal research. On November 11 of that year, he gave a commemorative lecture at the Kyoto International Conference Center.⁠[6][6][6][6]

The Kyoto Prize citation also noted that he co-founded a drug discovery startup using optogenetics and organizes workshops and training courses in his lab, welcoming young researchers aspiring to study optogenetics. The same year, he shared the Canada Gairdner International Award with Boyden and Hegemann.⁠[6][6][5]

In 2019, he was elected to the U.S. National Academy of Engineering and shared the Warren Alpert Foundation Prize with Boyden, Hegemann, and Miesenböck.⁠[2][7][5]

In 2020, the Royal Netherlands Academy of Arts and Sciences awarded him the Heineken Prize for Medicine for developing optogenetics and hydrogel-tissue chemistry, which makes biological tissue accessible to light and molecular probes.⁠[2][2]

On June 15, 2021, his 272-page book Projections: A Story of Human Emotions was published. Combining his research on the brain’s circuitry with his empathy for patients, the book uses mental illness to explore the origins of the human mind and emotions.⁠[8][8][8]

In September 2021, he shared the Albert Lasker Basic Medical Research Award with Dieter Oesterhelt and Peter Hegemann, and on October 20 of that year he gave the Lasker Public Lecture.⁠[9][10][10]

In 2022, he received the Louisa Gross Horwitz Prize for optogenetics.⁠[2]

He shared the 2023 Japan Prize in the field of Life Sciences with Gero Miesenböck of the University of Oxford for the development of methods that use genetically addressable light-sensitive membrane proteins to unravel neural circuit function; the citation noted that in 2005 he first showed that rat hippocampal neurons expressing channelrhodopsin-2 could be controlled by light on a millisecond timescale, and that he went on to reveal the relationships between specific inhibitory neuronal populations and gamma brain waves, and between the excitatory-inhibitory balance in the prefrontal cortex and social behavior. On April 13, 2023, he received the prize at the presentation ceremony in Tokyo.⁠[11][11][11][12]

In 2025, he received the Asan Award in Basic Medicine for the discovery of light-gated ion channel mechanisms and the development of optogenetics.⁠[2]

On October 5, 2026, the Nobel Assembly at Karolinska Institutet announced that the 2026 Nobel Prize in Physiology or Medicine would be awarded jointly to Deisseroth, Peter Hegemann of Humboldt University of Berlin, and Georg Nagel of the University of Würzburg “for their discoveries concerning light-gated ion channels and optogenetics”. Hegemann and Nagel discovered channelrhodopsins in single-celled algae, and Deisseroth transformed the protein into a light-controlled switch for nerve cells. The prize amount is 12 million Swedish kronor (about $1.2 million), shared equally among the three.⁠[13][13][13][13][13][12][14]

When the Nobel Committee called at 12:27 a.m. Pacific Time, he missed the call, and it then came through to the phone of his wife, Michelle Monje-Deisseroth. Then 54, he told the Associated Press that he is a physician-scientist and a psychiatrist who cares about patients with autism and depression, and that as a basic scientist he also wants to understand how the brain works.⁠[3][3][3][15][15][15]

That morning Stanford University held a virtual press conference attended by President Jonathan Levin, Dean of the School of Medicine Lloyd Minor, and Dean of the School of Engineering Jennifer Widom; Deisseroth also celebrated on campus at the James H. Clark Center. Stanford said he is the university’s 37th Nobel laureate.⁠[3][3][3][3][16]

He is board-certified by the American Board of Psychiatry and Neurology and continues to practice at Stanford, specializing in affective disorders and autism-spectrum disease and employing medications along with neural stimulation in treatment; he also directs undergraduate education in bioengineering at Stanford.⁠[7][7][2][17]

Beyond optogenetics, his lab developed hydrogel-tissue chemistry, beginning with CLARITY: replacing the lipids in brain tissue with a hydrogel makes the tissue transparent, facilitating the study of brain circuits. As a Simons Foundation Autism Research Initiative (SFARI) Investigator, he received support for applying CLARITY to donated postmortem brain tissue from individuals with autism.⁠[7][18][18]

He created the Stanford Optogenetics Innovation Laboratory, which allowed visiting scientists from around the world to come to Stanford to learn the technology, and he freely distributed materials including viral vectors, plasmids, and hardware designs and made protocols openly available; his technologies have spread to thousands of laboratories around the world.⁠[3][3][7]

He is a member of the U.S. National Academy of Medicine and the National Academy of Sciences.⁠[7][7]

Deisseroth Lab: Official website: https://dlab.stanford.edu/ (opens in a new window).⁠[2]

Stanford University: Official website: https://www.stanford.edu/ (opens in a new window).⁠[7]

Howard Hughes Medical Institute: Official website: https://www.hhmi.org/ (opens in a new window).⁠[19]