Bidirectional action of 5-HT on synaptic transmission in rat medial vestibular nucleus

Abstract

Event Abstract Back to Event Bidirectional action of 5-HT on synaptic transmission in rat medial vestibular nucleus Lei Han1* and Shing Y. Chan1 1 The University of Hong Kong, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, China To elucidate the role of serotonergic innervations from dorsal raphe nucleus to the medial vestibular nucleus (MV), whole-cell patch-clamp was employed to investigate the serotonergic modulation of synaptic transmission within the MV of rats. Perfusion of serotonin (5-hydroxytryptamine, 5-HT) to brainstem slices robustly facilitated both spontaneous inhibitory postsynaptic currents (sIPSCs) and spontaneous excitatory postsynaptic currents (sEPSCs) in a subgroup of MV neurons. This 5-HT-induced facilitation of both sIPSCs and sEPSCs was abolished in the presence of tetrodotoxin. The action of 5-HT on spontaneous synaptic transmission could be mimicked with application of 5-HT2 receptor agonist but was blocked with 5-HT2A receptor antagonist. On the other hand, 5-HT reduced the amplitude of evoked EPSCs (eEPSCs) and IPSCs (eIPSCs). This 5-HT-induced suppression of both evoked excitatory and inhibitory synaptic transmission was mediated by 5-HT1A receptors as verified by application of agonist and antagonist of 5-HT1A receptors. The change of paired-pulse ratio of both eEPSCs and eIPSCs during application of 5-HT and agonist of 5-HT1A receptors suggests the action site of 5-HT1A receptors is located on the presynaptic neurons. Our results therefore indicate that within the MV, 5-HT exerts bidirectional action on synaptic transmission through activation of 5-HT2A and 5-HT1A receptors expressed on presynaptic neurons. Keywords: Serotonin, neurotransmission, 5-HT1A, 5-HT2A, medial vestibular nucleus Conference: 14th Meeting of the Asian-Pacific Society for Neurochemistry, Kuala Lumpur, Malaysia, 27 Aug - 30 Aug, 2016. Presentation Type: YIC05: Young Investigator Colloquium 5 Topic: 14th Meeting of the Asian-Pacific Society for Neurochemistry Citation: Han L and Chan SY (2016). Bidirectional action of 5-HT on synaptic transmission in rat medial vestibular nucleus. Conference Abstract: 14th Meeting of the Asian-Pacific Society for Neurochemistry. doi: 10.3389/conf.fncel.2016.36.00071 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 2016; Published Online: 11 Aug 2016. * Correspondence: Dr. Lei Han, The University of Hong Kong, School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, Hong Kong, Hong Kong, China, hanleicosmic@hotmail.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 Lei Han Shing Y Chan Google Lei Han Shing Y Chan Google Scholar Lei Han Shing Y Chan PubMed Lei Han Shing Y Chan 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.