title: Vesicular zinc regulates the Ca2+ sensitivity of a subpopulation of presynaptic vesicles at hippocampal mossy fiber terminals.
abstract: Synaptic vesicles segregate into functionally diverse subpopulations within presynaptic terminals, yet there is no information about how this may occur. Here we demonstrate that a distinct subgroup of vesicles within individual glutamatergic, mossy fiber terminals contain vesicular zinc that is critical for the rapid release of a subgroup of synaptic vesicles during increased activity in mice. In particular, vesicular zinc dictates the Ca(2+) sensitivity of release during high-frequency firing. Intense synaptic activity alters the subcellular distribution of zinc in presynaptic terminals and decreases the number of zinc-containing vesicles. Zinc staining also appears in endosomes, an observation that is consistent with the preferential replenishment of zinc-enriched vesicles by bulk endocytosis. We propose that functionally diverse vesicle pools with unique membrane protein composition support different modes of transmission and are generated via distinct recycling pathways.
authors.affiliation: Department of Psychiatry and Neuroscience, Robert Giffard Research Center of Laval University, Québec, Québec, Canada.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lavoie
authors.forename: Danny V
authors.initials: DV
authors.lastname: Jeyaraju
authors.forename: Modesto R
authors.initials: MR
authors.lastname: Peralta
authors.forename: László
authors.initials: L
authors.lastname: Seress
authors.forename: Luca
authors.initials: L
authors.lastname: Pellegrini
authors.forename: Katalin
authors.initials: K
authors.lastname: Tóth
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D018698:Glutamic Acid / Q000378:metabolism; D051379:Mice; D055369:Miniature Postsynaptic Potentials / Q000502:physiology; D019599:Mossy Fibers, Hippocampal / Q000378:metabolism* / Q000648:ultrastructure; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000378:metabolism / Q000648:ultrastructure; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D015032:Zinc / Q000378:metabolism*
chemical_list: D018698:Glutamic Acid; D015032:Zinc; D002118:Calcium