Frequency-dependent kinetics and prevalence of kiss-and-run and reuse at hippocampal synapses studied with novel quenching methods

Neuron. 2006 Jan 19;49(2):243-56. doi: 10.1016/j.neuron.2005.12.018.

Abstract

The kinetics of exo-endocytotic recycling could restrict information transfer at central synapses if neurotransmission were entirely reliant on classical full-collapse fusion. Nonclassical fusion retrieval by kiss-and-run would be kinetically advantageous but remains controversial. We used a hydrophilic quencher, bromophenol blue (BPB), to help detect nonclassical events. Upon stimulation, extracellular BPB entered synaptic vesicles and quenched FM1-43 fluorescence, indicating retention of FM dye beyond first fusion. BPB also quenched fluorescence of VAMP (synaptobrevin-2)-EGFP, thus indicating the timing of first fusion of vesicles in the total recycling pool. Comparison with FM dye destaining revealed that kiss-and-run strongly prevailed over full-collapse fusion at low frequency, giving way to a near-even balance at high frequency. Quickening of kiss-and-run vesicle reuse was also observed at higher frequency in the average single vesicle fluorescence response. Kiss-and-run and reuse could enable hippocampal nerve terminals to conserve scarce vesicular resources when responding to widely varying input patterns.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bromphenol Blue
  • Cells, Cultured
  • Coloring Agents
  • Electric Stimulation
  • Endocytosis / physiology
  • Exocytosis / physiology
  • Green Fluorescent Proteins / metabolism
  • Hippocampus / physiology*
  • Kinetics
  • Neurons / physiology
  • Presynaptic Terminals / physiology
  • Pyridinium Compounds / metabolism
  • Quaternary Ammonium Compounds / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Synapses / physiology*
  • Synaptic Transmission / physiology*
  • Temperature

Substances

  • Coloring Agents
  • FM1 43
  • Pyridinium Compounds
  • Quaternary Ammonium Compounds
  • enhanced green fluorescent protein
  • Bromphenol Blue
  • Green Fluorescent Proteins