Neuron-glia interactions: P2X7 receptor, the new player of the astrocytic receptor team

Abstract

Event Abstract Back to Event Neuron-glia interactions: P2X7 receptor, the new player of the astrocytic receptor team Joao Oliveira1* 1 University of Leipzig, Faculty of Medicine, Germany The better understanding of neuron-glia interactions and their influence on synaptic neurotransmission in the prefrontal cortex (PFC) is crucial to address the implication of these interactions for emotional, cognitive and short-term memory processes. Once thought to be only supportive elements allowing optimal nerve communication, astrocytes are now recognized as fully-fledged partners in neuro-neuronal communication. Indeed, recent findings reported the release of glutamate and other neurotransmitters e.g. by the activation of astrocytic purinergic P2X7 receptors in cell culture systems. Astrocyte-released glutamate may be responsible for the differential activation of neuronal regulatory receptors. Functional evidence of P2X7 receptors was sought in astrocytes of rat and mice brain slices containing the PFC, using patch-clamp and immunohistochemical techniques. The application of the P2X7 receptor agonist dibenzoyl-ATP (Bz-ATP) and ATP itself both caused inward currents in whole-cell recordings from those astrocytes. P2X7 receptor-immunoreactivity was co-localized with astrocytic, but not neuronal or microglial markers on cells labelled after electrophysiological measurements with Lucifer Yellow. The inactivity of α,β-methylene ATP, as well as the potency increases of Bz-ATP and ATP in a low divalent cation (X2+) conditions suggested the involvement of P2X7 receptors. This idea was further supported by the inhibition of these current responses by PPADS and selective P2X7 receptor antagonists. The reversal potential of Bz-ATP was near 0 mV, indicating the opening of such cationic receptor-channels. In a low X2+ extracellular medium, ATP induced current responses in PFC astrocytes of wild-type mice, but not of the P2X7-/- knockouts. On the other hand, the activation of astrocytic P2X7 receptors failed to interfere directly with the synaptic transmission between pyramidal neurons of the PFC. In conclusion, cortical astrocytes of rats and mice possess functional P2X7 receptors mediating inward cationic currents near the resting membrane potential. These receptors may most likely participate in necrotic/apoptotic or proliferative reactions after stimulation by large quantities of ATP released by CNS injury, rather than mediate a direct influence in synaptic transmission under physiological states. Conference: 11th Meeting of the Portuguese Society for Neuroscience, Braga, Portugal, 4 Jun - 6 Jun, 2009. Presentation Type: Oral Presentation Topic: Symposium 1– Neuronal Communication Citation: Oliveira J (2009). Neuron-glia interactions: P2X7 receptor, the new player of the astrocytic receptor team. Front. Neurosci. Conference Abstract: 11th Meeting of the Portuguese Society for Neuroscience. doi: 10.3389/conf.neuro.01.2009.11.002 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: 04 Aug 2009; Published Online: 04 Aug 2009. * Correspondence: Joao Oliveira, University of Leipzig, Faculty of Medicine, Leipzig, Germany, nemoABS01@frontiersin.org 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 Joao Oliveira Google Joao Oliveira Google Scholar Joao Oliveira PubMed Joao Oliveira 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.