David Van Vactor is a Professor and Director of the Biological & Biomedical Sciences PhD Program at Harvard Medical School. His research focuses on the regulation of neuronal connectivity and synaptogenesis through genetic and molecular biology approaches. He investigates the cell biological mechanisms necessary for building and maintaining functional neural circuits. His early work concentrated on axon guidance and the roles of conserved neuronal receptors, particularly the receptor protein tyrosine phosphatase LAR. He has identified critical factors that regulate neuronal morphogenesis, including a network of proteins that coordinate actin and microtubule dynamics during neuronal development. His studies also explore the mechanisms controlling synaptic growth and morphogenesis, revealing pathways that have implications for cognitive disorders. His innovative research includes the use of microRNAs in regulating synapse development, allowing for detailed studies of neural development and functionality in model organisms such as Drosophila, Chick, and Xenopus.