Seeing the light: photobehavior in fruit fly larvae.

Understanding how sensory stimuli drive behavior requires a detailed understanding of the molecular and neural nature through which the stimuli are received and processed. The visual system of the fruit fly Drosophila melanogaster shares marked similarities to that of mammals. Although much focus has been given to the fly visual system, an even further simplified eye and brain makes the visual system of Drosophila larvae an excellent model for dissecting sensory processing and behavioral responses to light. Recent work has identified sensory and central brain neurons required for larval visual behaviors, including circadian rhythms. Here, we review the genes and neurons regulating visual processing in Drosophila larvae and discuss the implications of this work for furthering understanding of more complex visual systems.