Spatial and structural requirements for initiation of epileptiform activity in a model for Temporal Lobe Epilepsy

Abstract

Event Abstract Back to Event Spatial and structural requirements for initiation of epileptiform activity in a model for Temporal Lobe Epilepsy Claudia Böhm1, 2*, U. P. Froriep1, 2, U. Häussler3 and Ulrich Egert1, 2 1 Albert-Ludwigs-University, Germany 2 Bernstein Center for Computational Neuroscience , Germany 3 Albert-Ludwigs-University, Neurocenter, Germany The intrahippocampal kainate model for Mesial Temporal Lobe Epilepsy (MTLE) in mice reproduces histological and functional changes of human MTLE, including cell loss in CA3 and CA1, granule cell dispersion and mossy fiber sprouting. In both human MTLE and the mouse model changes of the glia network were reported. Extent and structural reorganization of the glia network, as well as details of glia-neuron interaction in seizure initiation, however, are currently not known. We recorded disinhibited hippocampal slices (bicuculline) from untreated (control-slices) and kainate injected mice (KA-slices) using microelectrode arrays (MEA). In KA-slices taken close to the injection site, EA could not be induced, whereas in distal KA-slices EA was readily elicited but the coherence of EA within hippocampal areas was lower than in control-slices (Häussler et al., SfN, 2007). We analyzed the spatio-temporal structure of EA as well as coherence within hippocampal subregions. In control-slices and KA-slices, EA could typically first be seen in CA1 or CA3, consisting of a low frequency LFP with spike activity superimposed. Activity in granule cell layer and hilus followed with approx. 5 – 10 ms delay. In most cases, EA was accompanied by largeamplitude oscillations ≥ 200 Hz, which were most prominent in the dentate gyrus. To identify glianeuron interaction during the initiation of epileptiform activity (EA), we pharmacologically attenuated the effect of glia-derived glutamate by blocking NR2B receptors (Ifenprodil). Preliminary results indicate that attenuation of glia-neuron interaction in KA-slices did not affect the IEIs or amplitude EA, but decreased coherence within the dentate gyrus. In contrast, in controlslices coherence increased or did not change. This suggests a synchronizing, pro-epileptic effect of glia-neuron interaction in the epileptic tissue, possibly required for the initiation and/or maintenance of spontaneous seizures in the epileptic brain. In contrast, in the healthy tissue, glia-neuron interaction might have a less pronounced role in synchronizing neuronal activity or might even help to prevent EA by desynchronizing neuronal activity. Supported by the German Federal Ministry of Education and Research (BMBF, 01GQ0420). Conference: Bernstein Symposium 2008, Munich, Germany, 8 Oct - 10 Oct, 2008. Presentation Type: Poster Presentation Topic: All Abstracts Citation: Böhm C, Froriep UP, Häussler U and Egert U (2008). Spatial and structural requirements for initiation of epileptiform activity in a model for Temporal Lobe Epilepsy. Front. Comput. Neurosci. Conference Abstract: Bernstein Symposium 2008. doi: 10.3389/conf.neuro.10.2008.01.033 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 13 Nov 2008; Published Online: 13 Nov 2008. * Correspondence: Claudia Böhm, Albert-Ludwigs-University, Freiburg, Germany, boehm@bccn.uni-freiburg.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Claudia Böhm U. P Froriep U. Häussler Ulrich Egert Google Claudia Böhm U. P Froriep U. Häussler Ulrich Egert Google Scholar Claudia Böhm U. P Froriep U. Häussler Ulrich Egert PubMed Claudia Böhm U. P Froriep U. Häussler Ulrich Egert Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.