Extinction of remote memory traces promotes structural remodeling of neurons in anterior cingulate and infralimbic cortices

Abstract

Event Abstract Back to Event Extinction of remote memory traces promotes structural remodeling of neurons in anterior cingulate and infralimbic cortices Gisella Vetere1, 2*, Massimiliano Aceti1, Martine Ammassari-Teule1, 2 and Leonardo Restivo3 1 S. Lucia Foundation, Italy 2 CNR Institute for Neuroscience, Italy 3 Hospital for Sick Children Research Institute, Program in Neurosciences and Mental Health, Canada Synaptic plasticity plays a crucial role in the progressive formation of long-lasting memory traces. We have recently demonstrated that structural remodeling of cortical neurons, i.e. dendritic spine growth, develops in the anterior cingulate cortex (aCC) during the formation of remote contextual fear memory. Here we show how this modifications develops in the aCC during the consolidation process. For this scope we trained mice in the CFC and tested them in 5 different time points. At the end of test sessions, the brains of the mice were processed for Golgi-cox to analyze morphological changes. Interestingly, despite an equivalent number of spines was counted in aCC on days 7, 14 and 21, the number of single neurons showing increased spine density strongly varied across time-points. These findings suggest that long term storage of the memory trace requires a relatively stable increase in spines provided by a variable number of recruited neurons. We then asked whether the same cortical wiring changes induced by the consolidation process may persist when the trace no longer controls the behavior and/or does no longer matches external contingencies. In order to address this question we trained mice in the fear extinction paradigm for remote memory. Mice were subjected to contextual fear conditioning and 36 days later they underwent a fear extinction protocol consisting of repeated exposures to the conditioning chamber (context) without footshocks causing fear responses to diminish. Our results show that remote memory extinction is associated with spine pruning in the aCC cortex. Interesting, we found that infralimbic (IL) cortex neurons increase their spine density after remote memories retrieval and its rewiring persists after extinction. These data point to the hypothesis that the aCC might play a role in the retrieval of the remote trace, while the IL might be devoted to the switching of behavioral output according to external contingencies and previous knowledge Conference: 41st European Brain and Behaviour Society Meeting, Rhodes Island, Greece, 13 Sep - 18 Sep, 2009. Presentation Type: Poster Presentation Topic: Poster presentations Citation: Vetere G, Aceti M, Ammassari-Teule M and Restivo L (2009). Extinction of remote memory traces promotes structural remodeling of neurons in anterior cingulate and infralimbic cortices. Conference Abstract: 41st European Brain and Behaviour Society Meeting. doi: 10.3389/conf.neuro.08.2009.09.341 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: 15 Jun 2009; Published Online: 15 Jun 2009. * Correspondence: Gisella Vetere, S. Lucia Foundation, Rome, Italy, gisella.vetere@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 Gisella Vetere Massimiliano Aceti Martine Ammassari-Teule Leonardo Restivo Google Gisella Vetere Massimiliano Aceti Martine Ammassari-Teule Leonardo Restivo Google Scholar Gisella Vetere Massimiliano Aceti Martine Ammassari-Teule Leonardo Restivo PubMed Gisella Vetere Massimiliano Aceti Martine Ammassari-Teule Leonardo Restivo 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.