Eileen M. Lafer, Ph. D. Professor of Biochemistry Director, UTHSCSA Center for Surface Plasmon Resonance Co-Director, UTHSCSA Center for Macromolecular Interactions The University of Texas Health Science Center at San Antonio Neurotransmission is a cycle of exo- and endocytosis. Following depolarization and calcium influx synaptic vesicles fuse with the presynaptic plasma membrane and release their neurotransmitter cargo into the synaptic cleft. The neurotransmitter molecules diffuse across the cleft and bind to receptors on the post-synaptic plasma membrane, thereby propagating the nerve impulse. The synaptic vesicle membrane proteins are then recovered by the presynaptic terminal, and re-utilized for the local biogenesis of new synaptic vesicles. We demonstrated that the clathrin pathway is essential for synaptic vesicle endocytosis. Now we are focused on dissecting the biochemical mechanisms that underlie clathrin coated vesicle assembly and uncoating. We utilize a wide range of techniques including solution biochemistry, electrophysiology and X-ray crystallography to gain insight into fundamental biological processes.