EARLY DEVELOPMENT OF THE DROSOPHILA MUSHROOM BODIES, BRAIN CENTERS FOR ASSOCIATIVE LEARNING AND MEMORY

We have studied the formation of Drosophila mushroom bodies using enha ncer detector techniques to visualize specific components of these com plex intrinsic brain structures. During embryogenesis, neuronal prolif eration begins in four mushroom body neuroblasts and the major axonal pathways of the mushroom bodies are pioneered. During larval developme nt, neuronal proliferation continues and further axonal projections in the pe dunculus and lobes are formed in a highly structured manner ch aracterized by spatial heterogeneity of reporter gene expression. Enha ncer detector analysis identifies many genomic locations that are spec ifically activated in mushroom body intrinsic neurons (Kenyon cells) d uring the transition from embryonic to postembryonic development and d uring metamorphosis.