Adenosine receptor levels in the rat hippocampus: Stress-induced changes

Abstract

Event Abstract Back to Event Adenosine receptor levels in the rat hippocampus: Stress-induced changes Vania L. Batalha1*, Ana Maria-Sebastiao1 and Luisa V. Lopes1 1 University of Lisbon, Institute of Pharmacology and Neurosciences, Institute of Molecular Medicine, Faculty of Medicine, Portugal Stress induced early in life interferes with the establishment, maintenance and development of neuronal networks. Some of these changes share similarities with those observed in aging (Miller et al., 2005 Aging Res. Rev., 4, 123). We have previously observed an imbalance in the density of the adenosine A1 and A2A receptors in the hippocampus and striatum of aged animals (Lopes et al., 1999, J. Neurochem., 73, 1733). We now investigated if the induction of chronic stress, through maternal separation, could have a similar impact on adenosine receptors.Male Wistar rats were assigned to either control (CTR) or maternal separated (MS) group. The MS were separated from their mothers for 3h/day (2-14 postnatal days) while CTR were left undisturbed. At 7-8 weeks of age they were sacrificed, the hippocampi and striata dissected and membranes or nerve terminals isolated. Saturation binding curves with the selective antagonist for A1 receptors, [3H]DPCPX (0-7 nM) or the selective antagonist for A2A receptors, [3H]ZM 241385 (0-7 nM) were performed. The displacement of [3H]DPCPX (2 nM) by the selective A1 receptor agonist, CPA (0-1 μM) in the presence of the selective A2A receptor agonist, CGS 21680 (30 nM) was assessed. The levels of presynaptic A2A receptors were quantified by immunoblot analysis in hippocampal synaptosomes.The A2A receptor immunoreactivity in hippocampal nerve terminals increased by 56.2% (±9.4%, P<0.05; n=3) in MS in relation to CTR animals. The levels of A1 receptors assessed by saturation assays seem to be unchanged, with a Bmax of 890.6 fmol/mg protein (95% Confidence Interval: 770.5-1011.0; n=3) for CTR animals and of 1002 fmol/mg protein (95% CI: 927.2-1077.0; n=3) for MS animals. The ability of the A2A selective agonist, CGS 21680 (10 nM) in reducing the affinity profile for A1 receptors, seen by displacement assays in the hippocampus, was not modified in MS animals (n=4). In the striatum, no differences in the binding density for the A2A antagonist, [3H]-ZM241385 (n=3) nor for the A1 antagonist, [3H]-DPCPX (n=3) were found.In hippocampus, neonatal stress induces a presynaptic increase in the A2A, as occurs in ageing, but not in the A1 receptor levels nor in their affinity. In contrast, in striatum, neither A1 nor A2A receptor levels are modified. These results suggest a differential effect of chronic stress in the hippocampus, which may result from the dominant expression of corticosteroid receptors in this brain area over others. Conference: 11th Meeting of the Portuguese Society for Neuroscience, Braga, Portugal, 4 Jun - 6 Jun, 2009. Presentation Type: Poster Presentation Topic: Neuronal Communication Citation: Batalha VL, Maria-Sebastiao A and Lopes LV (2009). Adenosine receptor levels in the rat hippocampus: Stress-induced changes. Front. Neurosci. Conference Abstract: 11th Meeting of the Portuguese Society for Neuroscience. doi: 10.3389/conf.neuro.01.2009.11.123 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 Aug 2009; Published Online: 11 Aug 2009. * Correspondence: Vania L Batalha, University of Lisbon, Institute of Pharmacology and Neurosciences, Institute of Molecular Medicine, Faculty of Medicine, Lisbon, Portugal, vbatalha@fm.ul.pt 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 Vania L Batalha Ana Maria-Sebastiao Luisa V Lopes Google Vania L Batalha Ana Maria-Sebastiao Luisa V Lopes Google Scholar Vania L Batalha Ana Maria-Sebastiao Luisa V Lopes PubMed Vania L Batalha Ana Maria-Sebastiao Luisa V Lopes 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.