Glial Regulation of Circuit Wiring, Firing, and Expiring in the Drosophila Central Nervous System

Molecular genetic approaches in small model organisms like Drosophila have helped to elucidate fundamental principles of neuronal cell biology. Much less is understood about glial cells, although interest in using invertebrate preparations to define their in vivo functions has increased significantly in recent years. This review focuses on our current understanding of the three major neuron-associated glial cell types found in the Drosophila central nervous system (CNS)-astrocytes, cortex glia, and ensheathing glia. Together, these cells act like mammalian astrocytes and microglia; they associate closely with neurons including surrounding neuronal cell bodies and proximal neurites, regulate synapses, and engulf neuronal debris. Exciting recent work has shown critical roles for these CNS glial cells in neural circuit formation, function, plasticity, and pathology. As we gain a more firm molecular and cellular understanding of how Drosophila CNS glial cells interact with neurons, it is clear that they share significant molecular and functional attributes with mammalian glia and will serve as an excellent platform for mechanistic studies of glial function.