title: Amperometric post spike feet reveal most exocytosis is via extended kiss-and-run fusion.
abstract: The basis for communication between nerve cells lies in the process of exocytosis, the fusion of neurotransmitter filled vesicles with the cell membrane resulting in release of the signaling molecules. Even though much is known about this process, the extent that the vesicles are emptied upon fusion is a topic that is being debated. We have analyzed amperometric peaks corresponding to release at PC12 cells and find stable plateau currents during the decay of peaks, indicating closing of the vesicle after incomplete release of its content. Using lipid incubations to alter the amount of transmitter released we were able to estimate the initial vesicular content, and from that, the fraction of release. We propose a process for most exocytosis events where the vesicle partially opens to release transmitter and then closes directly again, leaving the possibility for regulation of transmission within events.
authors.affiliation: University of Gothenburg, Department of Chemistry and Molecular Biology, 41296 Gothenburg, Sweden.
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Mellander
authors.forename: Raphaël
authors.initials: R
authors.lastname: Trouillon
authors.forename: Maria I
authors.initials: MI
authors.lastname: Svensson
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Ewing
mesh_terms: D000200:Action Potentials; D000818:Animals; D002450:Cell Communication / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D008081:Liposomes / Q000737:chemistry / Q000494:pharmacology; D008561:Membrane Fusion / Q000187:drug effects*; D008839:Microelectrodes; D018377:Neurotransmitter Agents / Q000378:metabolism*; D016716:PC12 Cells; D010743:Phospholipids / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D022142:Secretory Vesicles / Q000187:drug effects / Q000378:metabolism*; D055366:Synaptic Potentials / Q000187:drug effects; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: D008081:Liposomes; D018377:Neurotransmitter Agents; D010743:Phospholipids