Nobel Prize in Medicine awarded to scientists who pioneered work in optogenetics

Optogenetics "makes it possible to switch on, or off, the activity of individual nerve cells in a living brain," said Thomas Perlmann, secretary general of the Nobel Assembly at Karolinska ​Institutet.

"This method is now being used in laboratories around the world to reveal ​the brain's mysteries," he said.

Deisseroth, a 54-year-old American, Hegemann, a 71-year-old German, and Georg Nagel, a 73-year-old German, were all surprised to learn they had won, Perlmann said.

"All ‌three said the same thing, that they thought it was absolutely wonderful to receive the prize with the other two, and they call them … friends. That it's such an honour to receive them together. So that's something they conveyed," Perlmann said.