title: Nanoscale dynamics of synaptic vesicle trafficking and fusion at the presynaptic active zone.
abstract: The cytomatrix at the active zone (CAZ) is a macromolecular complex that facilitates the supply of release-ready synaptic vesicles to support neurotransmitter release at synapses. To reveal the dynamics of this supply process in living synapses, we used super-resolution imaging to track single vesicles at voltage-clamped presynaptic terminals of retinal bipolar neurons, whose CAZ contains a specialized structure-the synaptic ribbon-that supports both fast, transient and slow, sustained modes of transmission. We find that the synaptic ribbon serves a dual function as a conduit for diffusion of synaptic vesicles and a platform for vesicles to fuse distal to the plasma membrane itself, via compound fusion. The combination of these functions allows the ribbon-type CAZ to achieve the continuous transmitter release required by synapses of neurons that carry tonic, graded visual signals in the retina.
authors.affiliation: Department of Neurobiology and Behavior, Stony Brook University, New York, United States.
authors.forename: Thirumalini
authors.initials: T
authors.lastname: Vaithianathan
authors.affiliation: Department of Neurobiology and Behavior, Stony Brook University, New York, United States.
authors.forename: Diane
authors.initials: D
authors.lastname: Henry
authors.affiliation: Department of Neurobiology and Behavior, Stony Brook University, New York, United States.
authors.forename: Wendy
authors.initials: W
authors.lastname: Akmentin
authors.affiliation: Department of Neurobiology and Behavior, Stony Brook University, New York, United States.|Department of Ophthalmology, Stony Brook University, New York, United States.
authors.forename: Gary
authors.identifier: http://orcid.org/0000-0001-7915-9126
authors.initials: G
authors.lastname: Matthews
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001692:Biological Transport; D046911:Macromolecular Substances; D008853:Microscopy; D018408:Patch-Clamp Techniques; D017729:Presynaptic Terminals / Q000378:metabolism*; D013572:Synaptic Vesicles / Q000378:metabolism*; D015027:Zebrafish
chemical_list: D046911:Macromolecular Substances
keywords: neuroscience; presynaptic mechanisms; retina; synaptic transmission; zebrafish