Immunostaining of Drosophila Brains to Study Optic Lobe Development

The Drosophila optic lobe is a unique system to study neural development. It contains around 200 different types of neurons, which constitute four different neuropils: the lamina, medulla, lobula, and lobula plate. Neural development starts at the larval stage and ends at the pupal stage, resulting in a stereotypical structure at the adult stage. Here, we provide an immunostaining protocol for use on brains from larval, pupal, and adult stages, with a focus on different mounting orientations that can be used to study different aspects of optic lobe development. Images obtained using this protocol illustrate the complex structure of the optic lobe at different stages.