New Delhi: The 2026 Nobel Prize in Physiology or Medicine has been jointly awarded to Karl Deisseroth, Peter Hegemann and Georg Nagel for their work in optogenetics. The interdisciplinary field began as a technique through which researchers study how nerve cells shape memories, feelings, and behaviours in the living brain.
The prize money of 12 million Swedish kronor (almost Rs 11.5 crore) will be shared equally among the trio.
“Optogenetics provides opportunities for mapping the brain in a way that we could once only dream of,” said Per Svenningsson, Chair of the Nobel Committee for Physiology or Medicine, in a statement.
The Nobel-winning research began in the early 1990s with Hegemann’s curiosity about Chlamydomonas reinhardtii, a microscopic green alga that swims towards light. Hegemann, a biophysicist at Berlin’s Humboldt University, wanted to understand how the organism detects light.
Hegemann teamed up with Nagel, a molecular plant physiologist and biophysicist at the University of Würzburg, to probe into the alga. Their preliminary findings, published in 2003, detailed certain light-sensitive proteins called channelrhodopsins. These proteins act like tiny gates on a cell’s membrane. When blue light hits these proteins, they open, allowing electrically charged particles, also called ions, to pass through the cell membrane. These ions change the electrical composition of the cell and trigger the alga to respond to the light. The duo soon realised that when they put these proteins into a cell, the cell would become light sensitive.
In 2005, practising psychiatrist and professor of bioengineering and psychiatry at Stanford University, Karl Deisseroth, took their findings and applied them to neuroscience. He found a way of making neurons respond to blue light by introducing into them a gene that could make nerve cells light-sensitive. A technique that began with algae soon made its way to the human brain.
The technique gave scientists a way to test whether certain behaviours were linked to or caused by certain neurons. Researchers might have known that certain neurons become active when a memory is forming, but they can now manipulate these cells by turning them on and off using light to see whether the behaviour changes.
With their contributions, optogenetics has, over the years, become an indispensable tool to study neural circuits involved in memory, emotion, and behaviour, as well as psychiatric disorders.
“Using optogenetics, researchers have been able to reveal neural circuits governing specific memories, feelings, and behaviours relevant for neurological and psychiatric disorders. In clinical medicine, researchers are using the method in attempts to restore sight in people with visual impairment,” reads a press release by the Nobel Assembly at Karolinska Institutet.