Event Abstract Back to Event Organization of corticospinal projections in control and knockout-AC1 adult mice Nait T. Ali H.1, P. Gaspar2 and M. Bennis1* 1 Université Cadi Ayyad, Laboratoire de Pharmacologie, Neurobiologie et Comportement, Morocco 2 Institut du Fer-a-Moulin, INSERM U839, France Several guidance molecules are known to be involved at various decision points to regulate the projection of corticospinal axons. However, previous analyses of the corticospinal tract (CST) guidance defects in mutant mice lacking these molecules have suggested that there are other molecules involved in CST axon guidance that are yet to be identified. In this study, we investigate the role of cAMP signalling in the projection of motor CST axons in wild type and knockout-AC1 mice. To do so, we used in our study two different tracers: biotinylated Dextran amin (BDA) anterograde tracing of the motor CST axons and Fluorogold (FG) retrograde tracer to quantify the density of CST ipsilateral and controlateral projections on transverse sections at the level of high (C2-C4) and low cervical spinal cord (C5-C8). Our anterograde tracers show that in both controls and knockout mice, in the cervical spinal cord, many axons branched out from the crossed CST (main tract) to the dorsal and ventral horn. Some of these axons crossed to the ipsilateral grey matter. CST axons branch toward the lateral and ventral white matter. However, in knockout-AC1 mice, the main CST contained high number of labelled fibres than thus observed in controls in upper as well as in lower cervical spinal cord. The same observation was made for the ipsilateral CST. Interestingly the result of our retrograde tracing did not show a similar phenotype of labelled motor neurons in the cortex between controls and knockout-AC1 mice. Corticospinal neurons seem to be denser and closer to the midline in the latter group. It could be that In Vivo, the involvement of AC1 in the topographic organization of corticospinal tract is subtle, in contrast to what it has been shown for retinotectale and retinogeniculate systems. Although many questions remain, it is possible that other calcium-stimulated ACs, such as AC8, which is also expressed in the motor cortex, could be strongly involved in the organisation of these projections. It is evident that cAMP occupies a strategic position to control neuronal responses to a large variety of developmental cues that are important to investigate in the corticospinal tract axons in vitro. Conference: 2nd NEUROMED Workshop, Fez, Morocco, 10 Jun - 12 Jun, 2010. Presentation Type: Oral Presentation Topic: Oral Session 3: The plastic brain: implications for learning and education Citation: Ali H. NT, Gaspar P and Bennis M (2010). Organization of corticospinal projections in control and knockout-AC1 adult mice. Front. Neurosci. Conference Abstract: 2nd NEUROMED Workshop. doi: 10.3389/conf.fnins.2010.12.00036 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 Jun 2010; Published Online: 04 Jun 2010. * Correspondence: M. Bennis, Université Cadi Ayyad, Laboratoire de Pharmacologie, Neurobiologie et Comportement, Marrakech, Morocco, mbennis@ucam.ac.ma 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 Nait T Ali H. P. Gaspar M. Bennis Google Nait T Ali H. P. Gaspar M. Bennis Google Scholar Nait T Ali H. P. Gaspar M. Bennis PubMed Nait T Ali H. P. Gaspar M. Bennis 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.