Video 1

Movie S1. Light-induced stimulation of motor neurons in adult flies with ChR2-XXL. Activation of ChR2-XXL in motor neurons (driven by ok6-GAL4, plus retinal; Left) with white light LEDs (2.5 µW/mm2 at 460 nm) induced reversible immobilization of adult flies. In contrast, flies expressing ChR2-wt (plus retinal; Right) displayed no response.