Squeak, squeak, squeak … I sat at the lab bench grinding away at an optic fiber implant, polishing off the ends so the surface is even. My postdoctoral mentor said the implants I made had the best optical properties to shine blue light evenly and strongly onto its target, but I suspect he may have been trying to motivate me through the canonical undergraduate grunt work. Even the music playing through my headphones could not drown out the nails-on-a-chalkboard-like squeaks as the surface of the optic fiber was polished smooth. But to be a part of cutting-edge neuroscience research, it was worth it.
The optic fibers implant I was making would be used in conjunction with genetic engineering techniques to selectively turn on specific neurons in the brain using a simple flash of light. My undergraduate lab was one of many to adopt what had become a staple tool in neuroscience research. Earlier this month, on Oct. 5, 2026, the developers of this technology were announced as the awardees of the Nobel Prize in Physiology or Medicine, making Karl Deisseroth, Peter Hegemann and Georg Nagel among the newest Nobel laureates.1
The technique is called “optogenetics.” Opto- meaning light, -genetics referring to the step of altering the genome to express a light-sensitive receptor called channelrhodopsin in a neuron.
Channelrhodopsin was discovered from a seemingly inconsequential research question: How do single-celled algae detect the light they swim toward? It turned out that light exposure activates channelrhodopsin on the cell surface of these algae. Upon activation, a channel opens to allow charged ions though, which acts as an electrical signal triggering the algae’s movement toward the source of the light.1,2
Coincidentally, neurons use ion channels to create electrical signals, too! This made channelrhodopsin an ideal candidate for manipulating neuronal activation. Following up on this potential, channelrhodopsin was genetically inserted into cultured neurons and later into the neurons of living mice, making neuronal activation as simple as turning on a light.1 Thus, what began as a simple question with no obvious biomedical relevance became one of the most powerful tools in neuroscience research.
Genetic tools can be used to control which neurons express channelrhodopsin (for example, neurons from a specific brain region and/or of a certain cell type), and thus the experimenter can choose which neuron they manipulate in their experiment to understand the neuron’s function. For example, the optic fiber implants I spent hours grinding away at in my undergraduate lab were used to modulate neural activity in dopamine-related circuits affected by Parkinson’s disease. By expressing channelrhodopsin in different types of dopamine-producing cells within the basal ganglia (an area of the brain involved in movement), the lab studied which neurons in the circuit control different parts of a movement pattern,3 with the ultimate hope of understanding how movement is disrupted in Parkinson’s disease.
Optogenetic technology has potential for further innovation. Just last year at a conference, I met a fellow scientist who wanted to use optogenetics to shine light on the brain in a holographic manner — selectively targeting distinct neurons across a circuit. Compared to the relatively crude optic fiber implants I was familiar with, which activate all channelrhodopsin-expressing neurons within the vicinity, this technology would revolutionize the potential of optogenetics to target specific elements of a circuit! Translational researchers are looking into the potential of channelrhodopsin as a gene therapy approach for certain types of visual impairment. Theoretically, if the cause of a patient’s visual impairment is their retinal cell’s light receptors, then channelrhodopsin could be used to replace the nonfunctional light receptors.
This year’s Nobel Prize award demonstrates that even the most basic research questions with seemingly little human relevance have the potential to be transformative for the future of scientific and biomedical innovation. Congrats to Karl Deisseroth, Peter Hegemann and Georg Nagel for the 2026 Nobel Prize in Physiology or Medicine!
(1) Nobel Prize in Physiology or Medicine 2026. NobelPrize.org. https://www.nobelprize.org/prizes/medicine/2026/press-release/ (accessed 2026-10-06)
(2) Schneider, F.; Grimm, C.; Hegemann, P. Biophysics of Channelrhodopsin. Annu Rev Biophys 2015, 44, 167–186. https://doi.org/10.1146/annurev-biophys-060414-034014
(3) Klug, J. R.; Yan, X.; Hoffman, H.; Engelhardt, M. D.; Osakada, F.; Callaway, E. M.; Jin, X. Asymmetric Cortical Projections to Striatal Direct and Indirect Pathways Distinctly Control Actions. eLife 2025, 12, RP92992. https://doi.org/10.7554/eLife.92992
Related Content
- Nobel Prize Winning Research May Lead to New Therapies for Cancer, Alzheimer’s
- An Evening with Nobel Laureate Gregg Semenza
- Beyond the Renaissance: Nobel Laureates and Their Creative Pursuits
Want to read more from the Johns Hopkins School of Medicine? Subscribe to the Biomedical Odyssey blog and receive new posts directly in your inbox.