|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Use of Aldehyde Fixatives to Determine the Rate of Synaptic Transmitter Release
1 Section on Functional Neuroanatomy, National Institute of Neurological and Communicative Diseases and Stroke, National Institutes of Health, Bethesda, Maryland 20205, U.S.A.
Aldehyde fixation continues to be useful to prepare synapses for freeze-fracture, but it may increase the rate of transmitter release. The effects of different aldehyde fixatives on spontaneous quantal release (m.e.p.p.s), and on the corresponding synaptic vesicle exocytosis at frog nerve-muscle synapses were investigated with the hope of finding a way to minimize side effects of fixation. Increases in m.e.p.p.s of up to 50 s-1 occurred during fixation, despite the species of aldehyde used in the fixative, and this fixative effect decreased only slightly as aldehyde concentration was increased. Increases in m.e.p.p. frequency were not blocked by tetrodotoxin, by lowering external calcium and raising external magnesium concentration, or by lowering the total osmotic strength of the fixative. The smallest increase in m.e.p.p. frequency was in 3% glutaraldehyde and corresponded to the lowest level of synaptic vesicle exocytosis seen by freeze-fracture, 0·15per µm of active zone. The effects of aldehyde fixation on m.e.p.p. frequency and synaptic vesicle exocytosis could not be avoided, but this study suggests how its effect on morphological changes in synapses might be minimized.
This article has been cited by other articles:
|
|
 |
|
  G. Matthews and P. Sterling Evidence That Vesicles Undergo Compound Fusion on the Synaptic Ribbon J. Neurosci., May 21, 2008; 28(21): 5403 - 5411. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. O. Rizzoli and W. J. Betz The Structural Organization of the Readily Releasable Pool of Synaptic Vesicles Science, March 26, 2004; 303(5666): 2037 - 2039. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. D. Burgoyne and A. Morgan Secretory Granule Exocytosis Physiol Rev, April 1, 2003; 83(2): 581 - 632. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Satzler, L. F. Sohl, J. H. Bollmann, J. G. G. Borst, M. Frotscher, B. Sakmann, and J. H. R. Lubke Three-Dimensional Reconstruction of a Calyx of Held and Its Postsynaptic Principal Neuron in the Medial Nucleus of the Trapezoid Body J. Neurosci., December 15, 2002; 22(24): 10567 - 10579. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Abenavoli, L. Forti, M. Bossi, A. Bergamaschi, A. Villa, and A. Malgaroli Multimodal Quantal Release at Individual Hippocampal Synapses: Evidence for No Lateral Inhibition J. Neurosci., August 1, 2002; 22(15): 6336 - 6346. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Xu-Friedman, K. M. Harris, and W. G. Regehr Three-Dimensional Comparison of Ultrastructural Characteristics at Depressing and Facilitating Synapses onto Cerebellar Purkinje Cells J. Neurosci., September 1, 2001; 21(17): 6666 - 6672. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Lenzi, J. W. Runyeon, J. Crum, M. H. Ellisman, and W. M. Roberts Synaptic Vesicle Populations in Saccular Hair Cells Reconstructed by Electron Tomography J. Neurosci., January 1, 1999; 19(1): 119 - 132. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. H. Koenig, K. Yamaoka, and K. Ikeda Omega images at the active zone may be endocytotic rather than exocytotic: Implications for the vesicle hypothesis of transmitter release PNAS, October 13, 1998; 95(21): 12677 - 12682. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Schikorski and C. F. Stevens Quantitative Ultrastructural Analysis of Hippocampal Excitatory Synapses J. Neurosci., August 1, 1997; 17(15): 5858 - 5867. [Abstract] [Full Text] [PDF]
|
|
