Unraveling Mechanisms Allowing Spinal Cord Regeneration in an Inhibitory Milieu

Abstract

Event Abstract Back to Event Unraveling Mechanisms Allowing Spinal Cord Regeneration in an Inhibitory Milieu Fernando M. Mar1*, I. F. Carvalho2 and Mónica M. Sousa1 1 IBMC, Nerve Regeneration Group, Portugal 2 IBMC, Animal Facility, Portugal After a CNS injury, the glial scar is both a physical and a chemical barrier to regeneration. Nevertheless, when the peripheral branch of dorsal root ganglia (DRG) neurons is lesioned, prior to a lesion to their central branch (conditioning lesion), these central axons are able to overcome the inhibitory effect of the glial scar and regenerate to a significant extent. Currently, we are using the conditioning model to unravel enhancers of regeneration in an inhibitory environment. Of the possible mechanisms involved in regeneration, we focused on the study of the inflammatory response and axonal transport after injury.In order to address possible differences in inflammation, we performed complete hemograms where the systemic response was evaluated; no differences were observed between animals with spinal cord injury or conditioning lesion. Despite the lack of systemic differences, in vitro, serum collected from animals 1 day following sciatic nerve crush promoted an increased neurite outgrowth of DRG neurons. These results suggest that following a peripheral injury, nerve growth enhancing factors circulate in the plasma.To understand the importance of axonal transport of regeneration enhancers after conditioning lesion, DRG neurons were cultured with axoplasm from uninjured sciatic nerves or from nerve stumps of crushed sciatic nerves (proximal or distal to the crush site). Axoplasm from proximal nerve stumps did not alter neurite outgrowth. However, axoplasm from either distal or normal nerves impaired neurite outgrowth. Our results suggest the existence of regeneration inhibitors in the axoplasm from normal nerves and distal nerve stumps that are however inhibited proximally. As an alternative strategy to identify proteins differentially transported following conditioning lesions, we injected 35S labeled aminoacids in the spinal cord injury site of animals where either spinal cord lesion alone or conditioning lesions had been performed. Labeled transported proteins to the DRG in the different lesion models are currently being evaluated.In summary, we currently aim at identifying the putative regeneration enhancers present in the serum and axoplasm, as well as injury signals. The identification of such proteins may contribute to the development of new therapies for CNS injury. Conference: 11th Meeting of the Portuguese Society for Neuroscience, Braga, Portugal, 4 Jun - 6 Jun, 2009. Presentation Type: Poster Presentation Topic: Abstracts Citation: Mar FM, Carvalho IF and Sousa MM (2009). Unraveling Mechanisms Allowing Spinal Cord Regeneration in an Inhibitory Milieu. Front. Neurosci. Conference Abstract: 11th Meeting of the Portuguese Society for Neuroscience. doi: 10.3389/conf.neuro.01.2009.11.096 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: 10 Aug 2009; Published Online: 10 Aug 2009. * Correspondence: Fernando M Mar, IBMC, Nerve Regeneration Group, Porto, Portugal, Portugal.fmar@ibmc.up.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 Fernando M Mar I. F Carvalho Mónica M Sousa Google Fernando M Mar I. F Carvalho Mónica M Sousa Google Scholar Fernando M Mar I. F Carvalho Mónica M Sousa PubMed Fernando M Mar I. F Carvalho Mónica M Sousa 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.