ATP-dependent directional movement of rat synaptic vesicles injected into the presynaptic terminal of squid giant synapse Academic Article uri icon

Overview

MeSH Major

  • Adenosine Triphosphate
  • Synapses
  • Synaptic Vesicles

abstract

  • The question as to whether synaptic vesicles prepared from vertebrate brain can be transported to the active zones of the squid giant synapse was studied by using a combined optical and electrophysiological approach. In order to visualize the behavior of the vertebrate synaptic vesicles in situ, synaptic vesicles isolated from rat brain were labeled with a fluorescent dye (Texas red) and injected into the presynaptic terminal of the squid giant synapse. The pattern of fluorescence that would result from passive diffusion was determined by coinjection of an unconjugated fluorescent dye (fluorescein). The patterns obtained with fluorescent synaptic vesicles were strikingly different from that obtained by simple diffusion of fluorescein. Although the fluorescein diffused freely in both directions, the vesicles moved preferentially into the terminal--i.e., toward the release sites--at a rate of 0.5 microns/sec. The final distribution of the injected fluorescent synaptic vesicles displayed a discrete localization that suggested a distribution coincident with the active zones of the presynaptic terminal. Like fast axonal transport, but unlike fluorescein movements in the terminal, the vesicle movement was energy dependent, since the addition of 2,4-dinitrophenol blocked the redistribution of vesicles completely. In addition, reduction of extracellular calcium concentration reversibly blocked vesicular movement as well. In conclusion, mammalian synaptic vesicles retain the cytoplasmic surface components necessary for translocation, sorting, and targeting to the proper locations by the native machinery of the squid giant synapse.

publication date

  • January 1989

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC297683

PubMed ID

  • 2748609

Additional Document Info

start page

  • 5656

end page

  • 60

volume

  • 86

number

  • 14