The Science Behind the Nobel-Winning Technology That Controls Neurons With Light

The Karolinska Institute awarded the 2026 Nobel Prize successful Medicine to researchers Karl Deisseroth of Stanford University, Peter Hegemann of Humboldt University successful Berlin, and Georg Nagel of the University of Würzburg. Their discoveries led to the improvement of optogenetics, a method wherever scientists tin crook idiosyncratic nervus cells connected oregon disconnected utilizing beams of light.

According to Per Svenningsson, seat of the Nobel Committee for Medicine, “Optogenetics provides opportunities for mapping the encephalon successful a mode that we could erstwhile lone imagination of.” No different method allows for specified precise study of a surviving brain, helping researchers amended recognize the functions of our tense systems arsenic good arsenic assorted neurological diseases and disorders.

But this prize is not conscionable a solemnisation of neuroscience. It besides serves arsenic a triumphant illustration of what tin hap erstwhile antithetic disciplines of biology converge, arsenic the findings that served arsenic the ground for the improvement of optogenetics emerged from probe successful microbiology.

At the extremity of the past century, Peter Hegemann began a bid of studies to recognize however the single-celled alga Chlamydomonas is capable to observe and respond to light. Previous probe documented that Chlamydomonas has an “eye spot,” a tiny orangish dot connected its aboveground that contains a light-sensing molecule called retinal.

Hegemann utilized tiny electrodes to measurement the electrical signals generated by the alga and to grow our knowing of this structure’s accelerated response. The idiosyncratic discovered that the organism was susceptible of producing an electrical impulse astir 0.5 milliseconds aft receiving light. This effect clip is 20 times faster than that of the quality eye, whose airy detection process takes astatine slightest 10 milliseconds.

Hegemann suggested that airy detection successful the alga indispensable beryllium the effect of a overmuch simpler process than that identified successful the quality eye. In the aboriginal 1990s, helium projected that the oculus spots contained a macromolecule that some detected the airy and responded to it, apt opening arsenic a transmission to fto ions through. At the time, this proposal sparked controversy. Many ion channels had been documented up to that point, but nary could respond to airy connected their own.

To trial his theory, the idiosyncratic attempted to isolate the light-sensitive proteins from the oculus spot. However, erstwhile removed from their earthy environment, these proteins became unstable. Later, a radical of Japanese researchers sequenced the implicit DNA of Chlamydomonas, which allowed Hegemann’s squad to place 2 genes that would make proteins with the expected characteristics of a imaginable light-sensing channel.

Georg Nagel took the adjacent measurement of verifying the relation of the genes. He introduced copies of each of the identified genes separately into antithetic groups of frog eggs. The eggs began to nutrient the corresponding proteins, which yet localized to the compartment membranes. Nagel past turned connected the lights.