SummaryThe standfirst of the feature “Shining new light on the brain” (Curr. Biol. (2011), 21, R831–R833) stated that optogenetic control of neurons has only been around for six years. It has now come to our attention that the fundamental concept of targeting sensitivity to light to specific neurons, so that their electrical activity could be controlled optically, was established several years before the work on which the feature focused.