Ultrastructural Analysis of Proteins Implicated in Synaptic Vesicle Docking and Priming in C. elegans

Neurotransmitter release at synapses is mediated by the fusion of neurotransmitter containing synaptic vesicles (SV) with the presynaptic membrane. As neurotransmitter release is critical for integrating sensory inputs and for the subsequent cognitive and behavioral outcomes, it is highly regulated at every stage by cellular and molecular players. Research over the years have established SNARE (soluble-N-ethylmaleimide-sensitive factor attachment receptor) complex as the core synaptic vesicle fusion machinery. There are several other neuronal proteins that regulate SV fusion by directly or indirectly affecting SNARE complex assembly and its function. My thesis focuses on understanding the role of three such neuronal proteins: UNC-13 (Uncoordinated), SAX-7 (Sensory Axon Guidance), and VPS-39 (Vacuolar Protein Sorting). By studying the ultrastructural changes at the synapses, I contributed to the understanding of the function of these regulators in the critical SV fusion stage of neurotransmission.