| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Neurophysiology, University of Birmingham, Birmingham, United Kingdom
2 Mathematics, Case Western Reserve University, Cleveland, Ohio, USA
* To whom correspondence should be addressed. E-mail: j.g.r.jefferys{at}bham.ac.uk.
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.
This article has been cited by other articles:
|
|
 |
|
  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]
|
|
|
|
|
|
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]
|
|
|
|
|
|
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]
|
|
|
|
|
|
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]
|
|
|
|
 |
|
 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]
|
|
|
|
|
|
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]
|
|
|
|
 |
|
 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]
|
|
|
|
|
|
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 |
| Visit Other APS Journals Online |
