Nobel Medicine Prize Awarded to Three Scientists for Optogenetics Work

The Nobel Assembly at the Karolinska Institute in Stockholm named Karl Deisseroth of Stanford University and the Howard Hughes Medical Institute, Peter Hegemann of Humboldt University in Berlin and Georg Nagel of the University of Würzburg. The three share prize money of 12 million Swedish kronor, about $1.2 million, or roughly £901,500.

The Nobel committee wrote on X that the method "is now being used in laboratories around the world to reveal the brain's mysteries," according to NPR News. Thomas Perlmann, secretary of the medicine committee, said he was able to reach all three winners by telephone on Monday. NPR reported that Deisseroth is 54, Hegemann 71 and Nagel 73.

The research behind the prize began with a single-celled green alga, Chlamydomonas reinhardtii, which swims toward light. According to the Chinese science outlet QbitAI, Hegemann spent years studying how the alga senses light, work that led him and Nagel to identify the first channelrhodopsin in 2002 and to characterize channelrhodopsin-2, or ChR2, in 2003. They showed that ChR2 is itself a cation channel that light opens directly, allowing ions to cross the cell membrane and change its electrical potential.

In 2005, Deisseroth's team, working with Edward Boyden and Zhang Feng, introduced ChR2 into mammalian neurons and found that blue light alone could drive the cells to fire action potentials with millisecond precision. Because the light-sensitive protein can be expressed only in chosen cell types through genetic methods, researchers gained a way to activate or silence selected neurons at precise times and locations.

The approach turned a long-standing problem in neuroscience into an experimental method: instead of only observing which brain regions or neurons are active during memory formation, reward, movement or behavior, researchers could manipulate particular cells and watch whether behavior changed, weakening or disappearing. The technique has since been used to study memory, sleep, reward, addiction, motor control, anxiety, depression and social behavior, as well as the circuits involved in neurological and psychiatric disorders, QbitAI reported.

The Nobel citation pairs two strands of work: "light-gated ion channels," corresponding to the discovery and characterization of the microbial proteins by Hegemann and Nagel, and "optogenetics," corresponding to Deisseroth's development of molecular tools that brought those proteins into the nervous system as a way to control neural circuits.

The Guardian noted that this is the 117th time the medicine prize has been awarded. Of the 235 laureates, including this year's winners, 14 have been women.

Last year's medicine prize went to three scientists researching the immune system, NPR reported. The physics prize will be announced on Tuesday, chemistry on Wednesday, literature on Thursday and the peace prize on Friday, with the Nobel Memorial Prize in Economic Sciences to follow on Oct. 12.