Neuroscientist Dr. Karl Deisseroth, awarded the Nobel Prize for medicine, says his work has helped scientists pinpoint brain cells involved in disorders like depression and Alzheimer's ▻ ↧ US and German scientists win Nobel medicine prize for work on light... American Karl Deisseroth and Germans Peter Hegemann and Georg Nagel won the 2026 Nobel Prize in Physiology or Medicine on Monday for developing optogenetics, a technique that uses light to control individual nerve cells in the brain.