Three Scientists Win Nobel Medicine Prize for Developing Light-Controlled Brain Technology

The Nobel Prize in Medicine has been awarded to US psychiatrist and neurologist Karl Deisseroth and German scientists Peter Hegemann and Georg Nagel for their pioneering work in the field of optogenetics.

Optogenetics involves controlling nerve signals with light, and helps researchers understand how specific cell types contribute to behaviours like learning, fear, addiction and movement.

The trio was honoured on Monday “for their discovery of a molecular switch for nerve cells,” the Nobel Assembly said.

Using light, researchers are now able to switch individual neural circuits on or off in a brain.

They have been able to reveal neural circuits governing specific memories, feelings, and behaviours relevant for neurological and psychiatric disorders.

In clinical medicine, the method is being used in attempts to restore sight in people with visual impairment, and may one day lead to treatments for disorders such as Parkinson’s disease and epilepsy.

“Optogenetics provides opportunities for mapping the brain in a way that we could once only dream of,” Per Svenningsson, chair of the Nobel committee, said in a statement.

“Optogenetics has fundamentally altered our understanding of the brain. Every day brings new discoveries, helping to solve one of humanity’s great mysteries: how our incredible brain works,” the Nobel Assembly said.

The secretary general of the assembly, Thomas Perlmann, told reporters he was able to reach the three laureates by phone to break the news.

“That was great to talk to them. I first called Deisseroth; he was very tired when he answered. He was definitely asleep, but he woke up,” he said.

Illumination

In the early 2000s, Hegemann and Nagel were examining why a single-celled alga was able to swim toward a light source.

They discovered an algal protein with unique properties, called channelrhodopsin, found on the surface of the cell.

When illuminated by blue light, a channel opens through the protein.

Charged ions then flow into the cell, creating an electrical impulse.

They found that any cell they put the protein in became light-sensitive.

Deisseroth then introduced the gene for channelrhodopsin into nerve cells from rats.

By illuminating the cells with blue light, he was able to trigger a nerve signal.

He published his breakthrough in 2005, and two years later, made the light-controlled switch for nerve cells work in the brains of living mice.

In 2021, Deisseroth and Hegemann won the Lasker Prize for their work in the field, often considered a precursor to the Nobel.

Deisseroth, 54, is a professor at Stanford University in the US, while Hegemann, 71, is a neuroscience professor at Humboldt University of Berlin.