eLife (Oct 2017)

Frequency-dependent mobilization of heterogeneous pools of synaptic vesicles shapes presynaptic plasticity

  • Frédéric Doussau,
  • Hartmut Schmidt,
  • Kevin Dorgans,
  • Antoine M Valera,
  • Bernard Poulain,
  • Philippe Isope

DOI
https://doi.org/10.7554/eLife.28935
Journal volume & issue
Vol. 6

Abstract

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The segregation of the readily releasable pool of synaptic vesicles (RRP) in sub-pools that are differentially poised for exocytosis shapes short-term plasticity. However, the frequency-dependent mobilization of these sub-pools is poorly understood. Using slice recordings and modeling of synaptic activity at cerebellar granule cell to Purkinje cell synapses of mice, we describe two sub-pools in the RRP that can be differentially recruited upon ultrafast changes in the stimulation frequency. We show that at low-frequency stimulations, a first sub-pool is gradually silenced, leading to full blockage of synaptic transmission. Conversely, a second pool of synaptic vesicles that cannot be released by a single stimulus is recruited within milliseconds by high-frequency stimulation and support an ultrafast recovery of neurotransmitter release after low-frequency depression. This frequency-dependent mobilization or silencing of sub-pools in the RRP in terminals of granule cells may play a role in the filtering of sensorimotor information in the cerebellum.

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