A single-celled green alga swims toward light using a protein that opens like a gate. Georg Nagel, Peter Hegemann and colleagues described channelrhodopsin in 2002 and 2003, and in 2005 Karl Deisseroth's Stanford lab put it into neurons and switched them on with blue light. The episode tells the discovery fairly, from Francis Crick's wish to the 2026 Nobel Prize, and why a Nobel can name only three people.
Who's who
- Karl Deisseroth+3 more episodesStanford bioengineer and psychiatrist; 2026 Nobel laureate
- Peter Hegemann+1 more episodeBerlin biophysicist who studied the alga's light sensor; 2026 Nobel laureate
- Georg Nagel+1 more episodeBiophysicist and first author of the channelrhodopsin papers; 2026 Nobel laureate
- Francis CrickNamed the need for a switch for one cell type in 1979
- Dieter OesterheltBiochemist who identified bacteriorhodopsin in 1971
- Gero MiesenböckReported the first genetically targeted optical control of neurons in 2002
- Edward Boyden+1 more episodeStanford student and first author of the 2005 paper
- Feng ZhangGraduate student who built the vector for the 2005 paper
Where it happens
- Stanford University, California+8 more episodesWhere the 2005 neuron experiments were done
- Frankfurt, Germany+2 more episodesMax Planck Institute where Nagel and Bamberg worked
- Karolinska Institutet, Stockholm, SwedenAwarded the 2026 Nobel Prize
Timeline
- 1971Oesterhelt and Stoeckenius report bacteriorhodopsin
- January 2002Miesenböck's lab reports genetically targeted light control of neurons
- June 2002Channelrhodopsin-one reported in Science
- November 2003Channelrhodopsin-two shown to work in mammalian cells
- August 14, 2005Millisecond-timescale optical control of neurons published
- October 5, 2026Deisseroth, Hegemann and Nagel win the Nobel Prize
Still debated
Boyden and Deisseroth, both participants, emphasize different parts of the Stanford story, and the episode adjudicates neither. Whether Zhuo-Hua Pan should count as a discoverer, whether the founding moment is 2002 or 2005, and how much of the literature is confounded by heating are also argued.