Event Abstract Back to Event Differential effects of the brainstem on the maturation of GABAergic and glycinergic synapses on lumbar motoneurones in the rat Karina Sadlaoud1*, Sabrina Tazerart1, Cecile Brocard1, Celine Jean-Xavier1, Paule Portalier1, Frederic Brocard1, Laurent Vinay1 and Helene Bras1 1 Universite de la Mediterranee, Laboratoire Plasticite et Physio-Pathologie de la Motricite, UMR 6196 CNRS , France In immature spinal neurons, GABA- and glycine-evoked potentials are depolarizing and switch to a hyperpolarizing action during the first postnatal week. After neonatal spinal cord transection (SCT), this ontogenetic shift does not occur in lumbar Motoneurones (Mns). We investigated the effects of a complete neonatal SCT on the immuno-expression of Gly and GABAA receptors subunits (GlyR and GABAAR) in lumbar Mns. 7 days-old rats with neonatal SCT (S7) were compared to shams at P1 and P7. On S7, the membrane density of GlyRα1 was unchanged compared to P7. By contrast, the densities of GABAAR α2 and α3 subunits were significantly higher on S7 than on P7, and close to those reported at P1. Whole cell patch clamp recordings of mIPSCs performed in P7 vs S7 lumbar Mns revealed that the decay time of GABA but not glycine events was affected by SCT and the proportion of GABA events significantly increased, whereas the proportion of glycine and mixed events decreased. Serotoninergic axons arising from Raphe nuclei are among the earliest to reach the lumbar segments. Therefore, we tested the effects of a pharmacological activation of 5HT2R by the agonist DOI, which play a key role in the recovery of motor function after SCT, in S7 rats. After DOI treatment, GABAAR motoneuronal immunolabeling dropped down to values reported in P7, while Glyα1 labelling remained stable. We conclude that the plasticity of GlyR is independent of supraspinal influences whereas the plasticity of GABAAR is markedly influenced by descending pathways, in particular serotonergic projections. Keywords: GABAA receptors, glycine receptors, immunocytochemistry, spinal cord transection, whole cell patch recording Conference: 3rd Mediterranean Conference of Neuroscience , Alexandria, Egypt, 13 Dec - 16 Dec, 2009. Presentation Type: Poster Presentation Citation: Sadlaoud K, Tazerart S, Brocard C, Jean-Xavier C, Portalier P, Brocard F, Vinay L and Bras H (2009). Differential effects of the brainstem on the maturation of GABAergic and glycinergic synapses on lumbar motoneurones in the rat. Front. Neurosci. Conference Abstract: 3rd Mediterranean Conference of Neuroscience . doi: 10.3389/conf.neuro.01.2009.16.165 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: 26 Nov 2009; Published Online: 26 Nov 2009. * Correspondence: Karina Sadlaoud, Universite de la Mediterranee, Laboratoire Plasticite et Physio-Pathologie de la Motricite, UMR 6196 CNRS, 13331 Marseille, France, bras@dpm.cnrs-mrs.fr 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 Karina Sadlaoud Sabrina Tazerart Cecile Brocard Celine Jean-Xavier Paule Portalier Frederic Brocard Laurent Vinay Helene Bras Google Karina Sadlaoud Sabrina Tazerart Cecile Brocard Celine Jean-Xavier Paule Portalier Frederic Brocard Laurent Vinay Helene Bras Google Scholar Karina Sadlaoud Sabrina Tazerart Cecile Brocard Celine Jean-Xavier Paule Portalier Frederic Brocard Laurent Vinay Helene Bras PubMed Karina Sadlaoud Sabrina Tazerart Cecile Brocard Celine Jean-Xavier Paule Portalier Frederic Brocard Laurent Vinay Helene Bras 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.