Optogenetics is used to precisely control neural activity using light. This is achieved using light sensitive ion channels or opsins from the genomes of algae, archaea, and fungi. These opsins are then transduced into mammalian neurons via a viral vector, allowing the modified neurons to be modulated with millisecond precision. Additionally, opsins can be transduced in a cell-specific fashion using various targeting strategies.
A quantum leap beyond previous neuro-stimulation methods, optogenetics will facilitate the precise decomposition of functional circuitry of the brain at a level previously unimaginable.