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

Naturevolume 409pages479484 (2001) | Download Citation



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.

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We are grateful to W. Baumeister and members of the Department of Structural Biology at the Max-Planck Institute for Biochemistry in Martinsried, Germany, for use of their CM 200 electron microscope; A. Koster participated in the data collection for MPI-9 and MPI-10. We are also grateful to D. Agard and members of his laboratory in the Department of Biochemistry and Biophysics at the University of California San Francisco for use of the Philips EM 430; M. Braunfeld participated in the data collection for UC-1. T. Schwarz at Harvard Medical School provided comments on the manuscript, and B. Colyear at Stanford University made the schematic illustrations. This work was supported by grants from the NIH and the Deutsche Forschungsgemeinschaft, and by the M. A. Antelman Fund.

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  1. Department of Neurobiology, Stanford University School of Medicine, Stanford, 94305, California, USA

    • Mark L. Harlow
    • , David Ress
    • , Arne Stoschek
    • , Robert M. Marshall
    •  & Uel J. McMahan


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Correspondence to Uel J. McMahan.

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