A Physiologically Inspired Model for Global Remapping in the Hippocampus

Abstract

Event Abstract Back to Event A Physiologically Inspired Model for Global Remapping in the Hippocampus Axel J. Kammerer1, 2*, Alexander Mathis1, 2, 3, Martin Stemmler1, 3, Andreas V. Herz1, 3 and Christian Leibold1, 3 1 Ludwigs Maximilians Universitaet Muenchen, Division of Neurobiology, Germany 2 Graduate School of Systemic Neuroscience Munich, Germany 3 BCCN Munich, Germany Population activity patterns (place maps) in the hippocampus change dramatically if the animal is exposed to the same maze in different lab environments (global remapping) [Leutgeb et al. 2007, Science]. Such decorrelated patterns are essential for many models of associative memory: they sustain flexibility and allow many patterns to be stored. This remapping could have its root in an observed shift of grid cell firing patterns: During hippocampal remapping the spatial activity pattern of grid cells undergoes locally coherent rotations and translations [Fyhn et al. 2007, Nature], but it is not known whether this coherence extends over different spatial modules, which are anatomically separated within entorhinal cortex [Witter, Moser 2006, Trends in Neurosciences]. Also, the environment's size and shape are of importance for the remapping. We studied the influence of these realignments of grid cells on the formation of place cell firing patterns in the hippocampus and find that global remapping can indeed be caused by realigning a realistic number of grid cell modules. Also the size of the environment (relative to the grid field's period length) has influence on the remapping. To support these hypothesis, we employed a model with physiologically plausible connections in which grid cells give rise to place cells for a single environment [de Almeida et al. 2010, Hippocampus]. We investigate the behavior of the place cell output layer in response to incoherent rotations and translations of the spatial patterns in the grid cell modules in different sized environments, while leaving the synaptic weights from the grid to place layer unaltered. Simulations of the full model with noise create rate remapping for small shifts, leaving strong spatial correlations, while larger shifts produce strong rate fluctuations as well as spatial decorrelation of place fields. This recreates the findings in experiments by Fyhn et al. [Fyhn et al. 2007, Nature]. Furthermore the population vector decorrelation depends on the size of the environment, such that smaller shifts suffice to achieve the same decorrelation in larger environments. Keywords: grid cells, remapping Conference: Bernstein Conference 2012, Munich, Germany, 12 Sep - 14 Sep, 2012. Presentation Type: Poster Topic: Motor control, movement, navigation Citation: Kammerer AJ, Mathis A, Stemmler M, Herz AV and Leibold C (2012). A Physiologically Inspired Model for Global Remapping in the Hippocampus. Front. Comput. Neurosci. Conference Abstract: Bernstein Conference 2012. doi: 10.3389/conf.fncom.2012.55.00181 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: 11 May 2012; Published Online: 12 Sep 2012. * Correspondence: Mr. Axel J Kammerer, Ludwigs Maximilians Universitaet Muenchen, Division of Neurobiology, Munich, 82152, Germany, axel.kammerer@gmail.com 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 Axel J Kammerer Alexander Mathis Martin Stemmler Andreas V Herz Christian Leibold Google Axel J Kammerer Alexander Mathis Martin Stemmler Andreas V Herz Christian Leibold Google Scholar Axel J Kammerer Alexander Mathis Martin Stemmler Andreas V Herz Christian Leibold PubMed Axel J Kammerer Alexander Mathis Martin Stemmler Andreas V Herz Christian Leibold 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.