WWW.JNEUROSCI.ORG
-
The Journal of Neuroscience MBF Bioscience Neurolucida
QUICK SEARCH:   [advanced]


     
-


HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP
The Journal of Neuroscience, November 17, 2004, 24(46):10416-10430; doi:10.1523/JNEUROSCI.2074-04.2004

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit an eLetter
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
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
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (20)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gabriel, S.
Right arrow Articles by Lehmann, T.-N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gabriel, S.
Right arrow Articles by Lehmann, T.-N.

 Previous Article  |  Next Article 

Neurobiology of Disease
Stimulus and Potassium-Induced Epileptiform Activity in the Human Dentate Gyrus from Patients with and without Hippocampal Sclerosis

Siegrun Gabriel,1 * Marleisje Njunting,1 * Joern K. Pomper,1 Martin Merschhemke,3 Emilio R. G. Sanabria,4 Alexander Eilers,1 Anatol Kivi,1 Melanie Zeller,1 Heinz-Joachim Meencke,3 Esper A. Cavalheiro,4 Uwe Heinemann,1 {ddagger} and Thomas-Nicolas Lehmann1,2 {ddagger}

1Johannes Mueller Institute of Physiology, D-10117 Berlin, Germany, 2Department of Neurosurgery, Charité-University Medicine Berlin, D-13353 Berlin, Germany, 3Epilepsy Center of Berlin and Brandenburg, Evangelisches Krankenhaus Königin Elisabeth Herzberge, D-10362 Berlin, Germany, and 4Laboratorio de Neurologia Experimental, Universidade Federal de Sao Paulo-Escola Paulista de Medicina, 04023-900 Sao Paulo, Brazil

Hippocampal specimens resected to cure medically intractable temporal lobe epilepsy (TLE) provide a unique possibility to study functional consequences of morphological alterations. One intriguing alteration predominantly observed in cases of hippocampal sclerosis is an uncommon network of granule cells monosynaptically interconnected via aberrant supragranular mossy fibers. We investigated whether granule cell populations in slices from sclerotic and nonsclerotic hippocampi would develop ictaform activity when challenged by low-frequency hilar stimulation in the presence of elevated extracellular potassium concentration (10 and 12 mM) and whether the experimental activity differs according to the presence of aberrant mossy fibers.

We found that ictaform activity could be evoked in slices from sclerotic and nonsclerotic hippocampi (27 of 40 slices, 14 of 20 patients; and 11 of 22 slices, 6 of 12 patients, respectively). However, the two patient groups differed with respect to the pattern of ictaform discharges and the potassium concentration mandatory for its induction. Seizure-like events were already induced with 10 mM K+. They exclusively occurred in slices from sclerotic hippocampi, of which 80% displayed stimulus-induced oscillatory population responses (250-300 Hz). In slices from nonsclerotic hippocampi, atypical negative field potential shifts were predominantly evoked with 12 mM K+. In both groups, the ictaform activity was sensitive to ionotropic glutamate receptor antagonists and lowering of [Ca2+]o.

Our results show that, in granule cell populations of hippocampal slices from TLE patients, high K+-induced seizure-like activity and ictal spiking coincide with basic electrophysiological abnormalities, hippocampal sclerosis, and mossy fiber sprouting, suggesting that network reorganization could play a crucial role in determining type and threshold of such activity.

Key words: hippocampus; Ammon's horn sclerosis; mesial temporal lobe epilepsy; mossy fiber sprouting; high potassium; bicuculline; ictaform events

Received Oct 3, 2003; revised August 28, 2004; accepted October 2, 2004.




This article has been cited by other articles:


Home page
 Proc. Natl. Acad. Sci. USAHome page
E. Palma, C. Roseti, F. Maiolino, S. Fucile, K. Martinello, M. Mazzuferi, E. Aronica, M. Manfredi, V. Esposito, G. Cantore, et al.
GABAA-current rundown of temporal lobe epilepsy is associated with repetitive activation of GABAA "phasic" receptors
PNAS, December 26, 2007; 104(52): 20944 - 20948.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
F. Hamzei-Sichani, N. Kamasawa, W. G. M. Janssen, T. Yasumura, K. G. V. Davidson, P. R. Hof, S. L. Wearne, M. G. Stewart, S. R. Young, M. A. Whittington, et al.
Gap junctions on hippocampal mossy fiber axons demonstrated by thin-section electron microscopy and freeze fracture replica immunogold labeling
PNAS, July 24, 2007; 104(30): 12548 - 12553.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
J. Dyhrfjeld-Johnsen, V. Santhakumar, R. J. Morgan, R. Huerta, L. Tsimring, and I. Soltesz
Topological Determinants of Epileptogenesis in Large-Scale Structural and Functional Models of the Dentate Gyrus Derived From Experimental Data
J Neurophysiol, February 1, 2007; 97(2): 1566 - 1587.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
O. Kann and R. Kovacs
Mitochondria and neuronal activity
Am J Physiol Cell Physiol, February 1, 2007; 292(2): C641 - C657.
[Abstract] [Full Text] [PDF]

Home page
 BrainHome page
K. Jandova, D. Pasler, L. L. Antonio, C. Raue, S. Ji, M. Njunting, O. Kann, R. Kovacs, H.-J. Meencke, E. A. Cavalheiro, et al.
Carbamazepine-resistance in the epileptic dentate gyrus of human hippocampal slices
Brain, December 1, 2006; 129(12): 3290 - 3306.
[Abstract] [Full Text] [PDF]

Home page
 Sci SignalHome page
J. O. McNamara, Y. Z. Huang, and A. S. Leonard
Molecular Signaling Mechanisms Underlying Epileptogenesis
Sci. Signal., October 10, 2006; 2006(356): re12 - re12.
[Abstract] [Full Text] [PDF]

Home page
 Pharmacol. Rev.Home page
M. Raiteri
Functional pharmacology in human brain.
Pharmacol. Rev., June 1, 2006; 58(2): 162 - 193.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
D. Ragozzino, E. Palma, S. Di Angelantonio, M. Amici, A. Mascia, A. Arcella, F. Giangaspero, G. Cantore, G. Di Gennaro, M. Manfredi, et al.
Rundown of GABA type A receptors is a dysfunction associated with human drug-resistant mesial temporal lobe epilepsy
PNAS, October 18, 2005; 102(42): 15219 - 15223.
[Abstract] [Full Text] [PDF]

Home page
 BrainHome page
O. Kann, R. Kovacs, M. Njunting, C. J. Behrens, J. Otahal, T.-N. Lehmann, S. Gabriel, and U. Heinemann
Metabolic dysfunction during neuronal activation in the ex vivo hippocampus from chronic epileptic rats and humans
Brain, October 1, 2005; 128(10): 2396 - 2407.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
J. Epsztein, A. Represa, I. Jorquera, Y. Ben-Ari, and V. Crepel
Recurrent Mossy Fibers Establish Aberrant Kainate Receptor-Operated Synapses on Granule Cells from Epileptic Rats
J. Neurosci., September 7, 2005; 25(36): 8229 - 8239.
[Abstract] [Full Text] [PDF]


-

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help
-
Copyright 2008 by Society for Neuroscience ONLINE ISSN: 1529-2401
-