I have worked on structural synapse development and plasticity since 1980, when as a graduate student I received an NIH predoctoral fellowship in support of this work. During my career, I have served as a faculty member or co-director of several research and training programs at Harvard Medical School, Boston University, The Medical College of Georgia, and University of Texas at Austin. At each of these institutions I have trained undergraduate and graduate students, and postdoctoral and visiting fellows. I have recruited outstanding teams of research associates and research assistant professors who help in this training especially in the use of sophisticated methods for serial section electron microscopy and brain slice physiology. Together we provide a robust interface for collaborative efforts across cell, molecular, behavioral, and optogenetics approaches towards understanding the structural basis of synaptic transmission and plasticity. I have maintained an interest in the structural basis of synaptic plasticity when much of the field had initially turned away from cellular towards more molecular approaches. I have a robust track record of publishing break through findings about the structural basis of synaptic transmission. In recent years, there has been a profound and renewed interest in our work, as the field of Neuroscience has come to recognize the importance of nanometer resolution to investigate the mechanisms and development of neural circuitry and synapses. I am confident that I can continue to lead an outstanding team of scientists to meet the goals of the proposed research.