The architecture of active zone material at the frog's neuromuscular junction

Nature. 2001 Jan 25;409(6819):479-84. doi: 10.1038/35054000.


Active zone material at the nervous system's synapses is situated next to synaptic vesicles that are docked at the presynaptic plasma membrane, and calcium channels that are anchored in the membrane. Here we use electron microscope tomography to show the arrangement and associations of structural components of this compact organelle at a model synapse, the frog's neuromuscular junction. Our findings indicate that the active zone material helps to dock the vesicles and anchor the channels, and that its architecture provides both a particular spatial relationship and a structural linkage between them. The structural linkage may include proteins that mediate the calcium-triggered exocytosis of neurotransmitter by the synaptic vesicles during synaptic transmission.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium Channels / physiology
  • Image Enhancement
  • Membrane Proteins / physiology
  • Membrane Proteins / ultrastructure
  • Nerve Tissue Proteins / physiology
  • Nerve Tissue Proteins / ultrastructure
  • Neuromuscular Junction / physiology
  • Neuromuscular Junction / ultrastructure*
  • Organelles / physiology
  • Organelles / ultrastructure
  • Presynaptic Terminals / physiology
  • Presynaptic Terminals / ultrastructure
  • Rana pipiens
  • Synaptic Membranes / physiology
  • Synaptic Membranes / ultrastructure
  • Synaptic Vesicles / physiology
  • Synaptic Vesicles / ultrastructure


  • Calcium Channels
  • Membrane Proteins
  • Nerve Tissue Proteins