01 · The discovery
The idea, in everyday language
Knowing which neurons are active is different from knowing what they cause. Optogenetics lets researchers change the activity of selected cells and observe what follows.
Genes for light-sensitive proteins can be introduced into chosen cells. Light then changes the movement of ions across their membranes, allowing researchers to control activity with precise timing.
Why it matters
The method gives researchers a powerful way to test the roles of brain circuits in sensation, memory and behaviour.
