In this chapter, we present a detailed protocol for culturing the adult Drosophila brain ex vivo and discuss some of the possibilities this method opens up. Mature Drosophila brains can be easily maintained in culture for a long period of time, with very little deterioration. Explanting and culturing the brains using our technique solves the accessibility, immobilization, and visualization problems inherent in whole animal preparations. To illustrate the utility of this method, we discuss its application as a model to study the mechanisms of axon injury and regeneration. Until recently, axon regeneration has been studied mainly in vertebrate model organisms and neuronal cell cultures. However, the use of invertebrate models, which are much more amenable to genetic manipulation, shows great promise and should greatly accelerate our understanding of the molecular mechanisms of axon regeneration.