A readily retrievable pool of synaptic vesicles

Nat Neurosci. 2011 Jun 12;14(7):833-9. doi: 10.1038/nn.2838.

Abstract

Although clathrin-mediated endocytosis is thought to be the predominant mechanism of synaptic vesicle recycling, it seems to be too slow for fast recycling. Therefore, it was suggested that a presorted and preassembled pool of synaptic vesicle proteins on the presynaptic membrane might support a first wave of fast clathrin-mediated endocytosis. In this study we monitored the temporal dynamics of such a 'readily retrievable pool' of synaptic vesicle proteins in rat hippocampal neurons using a new type of probe. By applying cypHer5E, a new cyanine dye-based pH-sensitive exogenous marker, coupled to antibodies to luminal domains of synaptic vesicle proteins, we could reliably monitor synaptic vesicle recycling and demonstrate the preferential recruitment of a surface pool of synaptic vesicle proteins upon stimulated endocytosis. By using fluorescence nanoscopy of surface-labeled synaptotagmin 1, we could resolve the spatial distribution of the surface pool at the periactive zone in hippocampal boutons, which represent putative sites of endocytosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cells, Cultured
  • Endocytosis / genetics
  • Endocytosis / physiology
  • Hippocampus / cytology
  • Homer Scaffolding Proteins
  • Microscopy, Fluorescence / methods
  • Neurons / cytology*
  • Neurons / drug effects
  • Rats
  • Synapses / genetics
  • Synapses / physiology*
  • Synaptic Vesicles / physiology*
  • Transfection
  • Vesicular Inhibitory Amino Acid Transport Proteins / genetics
  • Vesicular Inhibitory Amino Acid Transport Proteins / metabolism

Substances

  • Carrier Proteins
  • Homer Scaffolding Proteins
  • Slc32a1 protein, rat
  • Vesicular Inhibitory Amino Acid Transport Proteins