JN AJP: Advances in Physiology Education
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Neurophysiol 90: 2402-2408, 2003. First published June 11, 2003; doi:10.1152/jn.00467.2003
0022-3077/03 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
90/4/2402    most recent
00467.2003v1
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 (14)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bikson, M.
Right arrow Articles by Jefferys, J. G.R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bikson, M.
Right arrow Articles by Jefferys, J. G.R.

Depolarization Block of Neurons During Maintenance of Electrographic Seizures

Marom Bikson1, Philip J. Hahn2, John E. Fox1 and John G.R. Jefferys1

1 Department of Neurophysiology, Division of Neuroscience, The Medical School, University of Birmingham, Birmingham B15 2TT, United Kingdom; 2 Department of Mathematics, Case Western Reserve University, Cleveland, Ohio 44106

Submitted 14 May 2003; accepted in final form 10 June 2003

Epileptic seizures are associated with neuronal hyperactivity. Here, however, we investigated whether continuous neuronal firing is necessary to maintain electrographic seizures. We studied a class of "low-Ca2+" ictal epileptiform bursts, induced in rat hippocampal slices, that are characterized by prolonged (2–15 s) interruptions in population spike generation. We found that, during these interruptions, neuronal firing was suppressed rather than desynchronized. Intracellular current injection, application of extracellular uniform electric fields, and antidromic stimulation showed that the source of action potential disruption was depolarization block. The duration of the extracellular potassium transients associated with each ictal burst was not affected by disruptions in neuronal firing. Application of phenytoin or veratridine indicated a critical role for the persistent sodium current in maintaining depolarization block. Our results show that continuous neuronal firing is not necessary for the maintenance of experimental electrographic seizures.

Address for reprint requests and other correspondence: J.G.R. Jefferys, Div. of Neuroscience (Neurophysiology), Univ. of Birmingham School of Medicine, Edgbaston, Birmingham B15 2TT, UK (E-mail: J.G.R.Jefferys{at}bham.ac.uk).




This article has been cited by other articles:


Home page
 J. Neurophysiol.Home page
D. S. Shin and P. L. Carlen
Enhanced Ih Depresses Rat Entopeduncular Nucleus Neuronal Activity From High-Frequency Stimulation or Raised Ke+
J Neurophysiol, May 1, 2008; 99(5): 2203 - 2219.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
P. Aracri, E. Colombo, M. Mantegazza, P. Scalmani, G. Curia, G. Avanzini, and S. Franceschetti
Layer-Specific Properties of the Persistent Sodium Current in Sensorimotor Cortex
J Neurophysiol, June 1, 2006; 95(6): 3460 - 3468.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
J. Ziburkus, J. R. Cressman, E. Barreto, and S. J. Schiff
Interneuron and Pyramidal Cell Interplay During In Vitro Seizure-Like Events
J Neurophysiol, June 1, 2006; 95(6): 3948 - 3954.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
S. Piccinin, A. D. Randall, and J. T. Brown
KCNQ/Kv7 Channel Regulation of Hippocampal Gamma-Frequency Firing in the Absence of Synaptic Transmission
J Neurophysiol, May 1, 2006; 95(5): 3105 - 3112.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
D. J. Pinto, S. L. Patrick, W. C. Huang, and B. W. Connors
Initiation, Propagation, and Termination of Epileptiform Activity in Rodent Neocortex In Vitro Involve Distinct Mechanisms
J. Neurosci., September 7, 2005; 25(36): 8131 - 8140.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
V. Santhakumar, I. Aradi, and I. Soltesz
Role of Mossy Fiber Sprouting and Mossy Cell Loss in Hyperexcitability: A Network Model of the Dentate Gyrus Incorporating Cell Types and Axonal Topography
J Neurophysiol, January 1, 2005; 93(1): 437 - 453.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
M. Vreugdenhil, E. Bracci, and J. G. R. Jefferys
Layer-specific pyramidal cell oscillations evoked by tetanic stimulation in the rat hippocampal area CA1 in vitro and in vivo
J. Physiol., January 1, 2005; 562(1): 149 - 164.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
J. E. Fox, M. Bikson, and J. G. R. Jefferys
Tissue Resistance Changes and the Profile of Synchronized Neuronal Activity During Ictal Events in the Low-Calcium Model of Epilepsy
J Neurophysiol, July 1, 2004; 92(1): 181 - 188.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online
Copyright © 2003 by the The American Physiological Society.