How a Tiny Green Alga Gave Us a Light Switch for the Brain

A simple question about pond algae led scientists to a way of turning brain cells on and off with a flash of blue light. This is the story of optogenetics, told step by step.​A simple question about pond algae led scientists to a way of turning brain cells on and off with a flash of blue light. This is the story of optogenetics, told step by step.