ON and OFF pathways in Drosophila motion vision

Ramon y Cajal, the founding father of neuroscience, observed similarities between the vertebrate retina and the insect eye, but that was based purely on anatomy. Using state-of-the-art genetics and electrophysiology in the fruitfly, these authors distinguish motion-sensitive neurons responding to abrupt increases in light from those specific to light decrements, thus bringing the similarity with vertebrate circuitry to the functional level.