title: Molecular underpinnings of synaptic vesicle pool heterogeneity.
abstract: Neuronal communication relies on chemical synaptic transmission for information transfer and processing. Chemical neurotransmission is initiated by synaptic vesicle fusion with the presynaptic active zone resulting in release of neurotransmitters. Classical models have assumed that all synaptic vesicles within a synapse have the same potential to fuse under different functional contexts. In this model, functional differences among synaptic vesicle populations are ascribed to their spatial distribution in the synapse with respect to the active zone. Emerging evidence suggests, however, that synaptic vesicles are not a homogenous population of organelles, and they possess intrinsic molecular differences and differential interaction partners. Recent studies have reported a diverse array of synaptic molecules that selectively regulate synaptic vesicles' ability to fuse synchronously and asynchronously in response to action potentials or spontaneously irrespective of action potentials. Here we discuss these molecular mediators of vesicle pool heterogeneity that are found on the synaptic vesicle membrane, on the presynaptic plasma membrane, or within the cytosol and consider some of the functional consequences of this diversity. This emerging molecular framework presents novel avenues to probe synaptic function and uncover how synaptic vesicle pools impact neuronal signaling.
authors.affiliation: Department of Neuroscience, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9111, USA.
authors.forename: Devon C
authors.initials: DC
authors.lastname: Crawford
authors.forename: Ege T
authors.initials: ET
authors.lastname: Kavalali
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D006801:Humans; D018377:Neurotransmitter Agents / Q000378:metabolism; D013570:Synaptic Membranes / Q000378:metabolism / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*; D013572:Synaptic Vesicles / Q000378:metabolism / Q000502:physiology*
chemical_list: D018377:Neurotransmitter Agents
keywords: SNARE proteins; asynchronous neurotransmission; neurotransmitter release; spontaneous neurotransmission; synaptic transmission; synaptic vesicle; synchronous neurotransmission; vesicle exocytosis; vesicle pools