Assembling trans-SNARE complexes function as the core fusion machinery that exerts mechanical force on adjoining membranes to induce membrane merger. Yet, the reorganization of lipid bilayers leading to putative fusion intermediates as well as fundamental structures of the nascent fusion pore, which mediates first release of neurotransmitter from the vesicle, are not well understood. Using a combination of high-resolution membrane capacitance measurements, carbon fiber amperometry, and ultrastructural analyses this project aims to characterize crucial proteins and lipid components facilitating membrane fusion.