JN Add DOIs to your references at manuscript stage!
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Neurophysiol 97: 3460-3472, 2007. First published February 21, 2007; doi:10.1152/jn.01288.2006
0022-3077/07 $8.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
97/5/3460    most recent
01288.2006v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (6)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Meeks, J. P.
Right arrow Articles by Mennerick, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Meeks, J. P.
Right arrow Articles by Mennerick, S.

Action Potential Initiation and Propagation in CA3 Pyramidal Axons

Julian P. Meeks1,2 and Steven Mennerick1,3

1Departments of Psychiatry and 3Anatomy and Neurobiology and 2Graduate Program in Neuroscience, Washington University School of Medicine, St. Louis, Missouri

Submitted 8 December 2006; accepted in final form 16 February 2007

Thin, unmyelinated axons densely populate the mammalian hippocampus and cortex. However, the location and dynamics of spike initiation in thin axons remain unclear. We investigated basic properties of spike initiation and propagation in CA3 neurons of juvenile rat hippocampus. Sodium channel alpha subunit distribution and local applications of tetrodotoxin demonstrate that the site of first threshold crossing in CA3 neurons is ~35 µm distal to the soma, somewhat more proximal than our previous estimates. This discrepancy can be explained by the finding, obtained with simultaneous whole cell somatic and extracellular axonal recordings, that a zone of axon stretching to ~100 µm distal to the soma reaches a maximum rate of depolarization nearly synchronously by the influx of sodium from the high-density channels. Models of the proximal axon incorporating observed distributions of sodium channel staining recapitulated salient features of somatic and axonal spike waveforms, including the predicted initiation zone, characteristic spike latencies, and conduction velocity. The preferred initiation zone was unaltered by stimulus strength or repetitive spiking, but repetitive spiking increased threshold and significantly slowed initial segment recruitment time and conduction velocity. Our work defines the dynamics of initiation and propagation in hippocampal principal cell axons and may help reconcile recent controversies over initiation site in other axons.

Address for reprint requests and other correspondence: S. Mennerick, Dept. of Psychiatry, Washington University School of Medicine, 660 S. Euclid Ave., Box 8134, St. Louis, MO 63110 (E-mail: menneris{at}psychiatry.wustl.edu)




This article has been cited by other articles:


Home page
 J. Neurosci.Home page
A. W. Ballo and D. Bucher
Complex Intrinsic Membrane Properties and Dopamine Shape Spiking Activity in a Motor Axon
J. Neurosci., April 22, 2009; 29(16): 5062 - 5074.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
S. I. Fried, A. C. W. Lasker, N. J. Desai, D. K. Eddington, and J. F. Rizzo 3rd
Axonal Sodium-Channel Bands Shape the Response to Electric Stimulation in Retinal Ganglion Cells
J Neurophysiol, April 1, 2009; 101(4): 1972 - 1987.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
A. Lorincz and Z. Nusser
Cell-Type-Dependent Molecular Composition of the Axon Initial Segment
J. Neurosci., December 31, 2008; 28(53): 14329 - 14340.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
J. F. Atherton, D. L. Wokosin, S. Ramanathan, and M. D. Bevan
Autonomous initiation and propagation of action potentials in neurons of the subthalamic nucleus
J. Physiol., December 1, 2008; 586(23): 5679 - 5700.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
M. Royeck, M.-T. Horstmann, S. Remy, M. Reitze, Y. Yaari, and H. Beck
Role of Axonal NaV1.6 Sodium Channels in Action Potential Initiation of CA1 Pyramidal Neurons
J Neurophysiol, October 1, 2008; 100(4): 2361 - 2380.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
G. J. Kress, M. J. Dowling, J. P. Meeks, and S. Mennerick
High Threshold, Proximal Initiation, and Slow Conduction Velocity of Action Potentials in Dentate Granule Neuron Mossy Fibers
J Neurophysiol, July 1, 2008; 100(1): 281 - 291.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
C. Schmidt-Hieber, P. Jonas, and J. Bischofberger
Action potential initiation and propagation in hippocampal mossy fibre axons
J. Physiol., April 1, 2008; 586(7): 1849 - 1857.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
J. N. Mercer, C. S. Chan, T. Tkatch, J. Held, and D. J. Surmeier
Nav1.6 Sodium Channels Are Critical to Pacemaking and Fast Spiking in Globus Pallidus Neurons
J. Neurosci., December 5, 2007; 27(49): 13552 - 13566.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
L. L. Scott, T. A. Hage, and N. L. Golding
Weak action potential backpropagation is associated with high-frequency axonal firing capability in principal neurons of the gerbil medial superior olive
J. Physiol., September 1, 2007; 583(2): 647 - 661.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2007 by the The American Physiological Society.