title: Bassoon speeds vesicle reloading at a central excitatory synapse.
abstract: Sustained rate-coded signals encode many types of sensory modalities. Some sensory synapses possess specialized ribbon structures, which tether vesicles, to enable high-frequency signaling. However, central synapses lack these structures, yet some can maintain signaling over a wide bandwidth. To analyze the underlying molecular mechanisms, we investigated the function of the active zone core component Bassoon in cerebellar mossy fiber to granule cell synapses. We show that short-term synaptic depression is enhanced in Bassoon knockout mice during sustained high-frequency trains but basal synaptic transmission is unaffected. Fluctuation and quantal analysis as well as quantification with constrained short-term plasticity models revealed that the vesicle reloading rate was halved in the absence of Bassoon. Thus, our data show that the cytomatrix protein Bassoon speeds the reloading of vesicles to release sites at a central excitatory synapse.
authors.affiliation: Carl Ludwig Institute of Physiology, Medical Faculty, University of Leipzig, Liebigstrasse 27, 04103 Leipzig, Germany. hallermann@medizin.uni-leipzig.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Hallermann
authors.forename: Anna
authors.initials: A
authors.lastname: Fejtova
authors.forename: Hartmut
authors.initials: H
authors.lastname: Schmidt
authors.forename: Annika
authors.initials: A
authors.lastname: Weyhersmüller
authors.forename: R Angus
authors.initials: RA
authors.lastname: Silver
authors.forename: Eckart D
authors.initials: ED
authors.lastname: Gundelfinger
authors.forename: Jens
authors.initials: J
authors.lastname: Eilers
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002531:Cerebellum / Q000378:metabolism / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000235:genetics / Q000502:physiology*; D006624:Hippocampus / Q000378:metabolism / Q000502:physiology; D051379:Mice; D057507:Mice, 129 Strain; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D009433:Neural Inhibition / Q000235:genetics / Q000502:physiology; D011930:Reaction Time / Q000235:genetics / Q000502:physiology; D013569:Synapses / Q000378:metabolism* / Q000502:physiology; D013572:Synaptic Vesicles / Q000378:metabolism* / Q000502:physiology; D013997:Time Factors
chemical_list: C498441:Bsn protein, mouse; D009419:Nerve Tissue Proteins