help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Biophys. J. BioFAST: First Published July 28, 2006. doi:10.1529/biophysj.106.084814
© 2006 by the Biophysical Society.

A more recent version of this article appeared on October 15, 2006.
This Article
Right arrow Full Text (Rapid PDF)
Right arrow All Versions of this Article:
biophysj.106.084814v1
91/8/2910    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zampighi, G. A
Right arrow Articles by Wright, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zampighi, G. A
Right arrow Articles by Wright, E.

MEMBRANES

CONICAL ELECTRON TOMOGRAPHY OF A CHEMICAL SYNAPSE: VESICLES DOCKED TO THE ACTIVE ZONE ARE HEMI-FUSED

Guido A Zampighi 1*, Lorenzo Zampighi 1, Nicholas Fain 1, Salvatore Lanzavecchia 2, Sidney Simon 3 and Ernest Wright 1

1 UCLA School Medicine
2 University of Milan, Italy
3 Duke University

* To whom correspondence should be addressed. E-mail: gzampighi{at}mednet.ucla.edu.

Submitted on March 10, 2006
Revised on April 11, 2006
Accepted on 31 May 2006


  Abstract
We have used thin sectioning and conical electron tomography to determine the 3D structure of synaptic vesicles that were associated ("docked") at release sites of the pre-synaptic membrane, called "active zones". Vesicles docked at the active zone occupied a strategic location: they formed regions of contact with the plasma membrane on one side and with that of one or more vesicles located deeper within the pre-synaptic terminal on the other side. The region of contact with the active zone measured 20-25 nm in diameter (~4% of the vesicle' surface) and contained a smaller ~8 nm region where the proximal leaflets merged (hemi-fused). Hemi-fusion was only observed on the side of vesicles in contact with the active zone; at the side of contact between neighboring vesicles, the membranes were not hemi-fused. Approximately three-fourths of the docked vesicles contained hemi-fused regions. Vesicles fully fused to the active zone (exhibiting "pores" that appeared as interruptions of a single membrane) were less frequently observed (~1 out of 10 hemi-fused vesicles). In conclusion, our observations in cortical synapses strengthen the hypothesis that hemi-fusion is a stable intermediary that precedes full fusion and release.

Key Words: chemical synapses, docked vesicles, fusion pores, hemifusion, synaptic vesicles




This article has been cited by other articles:


Home page
 Am. J. Physiol. Renal Physiol.Home page
D. B. N. Lee, N. Jamgotchian, S. G. Allen, M. B. Abeles, and H. J. Ward
A lipid-protein hybrid model for tight junction
Am J Physiol Renal Physiol, December 1, 2008; 295(6): F1601 - F1612.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
G. A. Zampighi, N. Fain, L. M. Zampighi, F. Cantele, S. Lanzavecchia, and E. M. Wright
Conical Electron Tomography of a Chemical Synapse: Polyhedral Cages Dock Vesicles to the Active Zone
J. Neurosci., April 16, 2008; 28(16): 4151 - 4160.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
T. Liu, T. Wang, E. R. Chapman, and J. C. Weisshaar
Productive Hemifusion Intermediates in Fast Vesicle Fusion Driven by Neuronal SNAREs
Biophys. J., February 15, 2008; 94(4): 1303 - 1314.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2006 by the Biophysical Society.