Visual place learning in Drosophila melanogaster

Abstract

Insects such as ants or bees are renowned for their navigational prowess, which in part derives from their ability to learn and associate visual cues to locations in space. Now Charles Zuker and colleagues demonstrate that a powerful model organism — Drosophila melanogaster — is also capable of using vision to form spatial memories. By genetically silencing specific neurons, they then show that such spatial learning relies on a brain centre (the ellipsoid body) which is distinct from that used for non-spatial learning (the mushroom body). This work could lead to Drosophila becoming a model of choice for the study of spatial memory. The ability of insects to learn and navigate to specific locations in the environment has fascinated naturalists for decades. The impressive navigational abilities of ants, bees, wasps and other insects demonstrate that insects are capable of visual place learning1,2,3,4, but little is known about the underlying neural circuits that mediate these behaviours. Drosophila melanogaster (common fruit fly) is a powerful model organism for dissecting the neural circuitry underlying complex behaviours, from sensory perception to learning and memory. Drosophila can identify and remember visual features such as size, colour and contour orientation5,6. However, the extent to which they use vision to recall specific locations remains unclear. Here we describe a visual place learning platform and demonstrate that Drosophila are capable of forming and retaining visual place memories to guide selective navigation. By targeted genetic silencing of small subsets of cells in the Drosophila brain, we show that neurons in the ellipsoid body, but not in the mushroom bodies, are necessary for visual place learning. Together, these studies reveal distinct neuroanatomical substrates for spatial versus non-spatial learning, and establish Drosophila as a powerful model for the study of spatial memories.