Multiple roles of ephrins during the formation of thalamocortical projections: Maps and more

Authors

  • Jürgen Bolz,

    Corresponding author
    1. Universität Jena, Institut für Allgemeine Zoologie und Tierphysiologie, Erberstrasse 1, 07743 Jena, Germany
    • Universität Jena, Institut für Allgemeine Zoologie und Tierphysiologie, Erberstrasse 1, 07743 Jena, Germany
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  • Daniela Uziel,

    1. Universität Jena, Institut für Allgemeine Zoologie und Tierphysiologie, Erberstrasse 1, 07743 Jena, Germany
    Current affiliation:
    1. Programa de Neurobiologia, IBCCF, UFRJ, Rio de Janeiro - RJ, Brazil
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  • Sven Mühlfriedel,

    1. Universität Jena, Institut für Allgemeine Zoologie und Tierphysiologie, Erberstrasse 1, 07743 Jena, Germany
    Current affiliation:
    1. Department of Molecular Cell Biology, Max-Planck-Institute für Biophysikalische Chemie, Göttingen, Germany
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  • André Güllmar,

    1. Universität Jena, Institut für Allgemeine Zoologie und Tierphysiologie, Erberstrasse 1, 07743 Jena, Germany
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  • Christiane Peuckert,

    1. Universität Jena, Institut für Allgemeine Zoologie und Tierphysiologie, Erberstrasse 1, 07743 Jena, Germany
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  • Konstantionos Zarbalis,

    1. Max-Planck-Institut für Psychiatrie, Kraeplinstrasse 2, 80804 München, Germany
    2. GSF-Research Center for Environment and Health, Ingolstädter Landstrasse. 1, 85764 Neuherberg, Germany
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  • Wolfgang Wurst,

    1. Max-Planck-Institut für Psychiatrie, Kraeplinstrasse 2, 80804 München, Germany
    2. GSF-Research Center for Environment and Health, Ingolstädter Landstrasse. 1, 85764 Neuherberg, Germany
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  • Masaaki Torii,

    1. John F. Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tennessee 37203
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  • Pat Levitt

    1. John F. Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tennessee 37203
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Abstract

The functional architecture of the cerebral cortex is based on intrinsic connections that precisely link neurons from distinct cortical laminae as well as layer-specific afferent and efferent projections. Experimental strategies using in vitro assays originally developed by Friedrich Bonhoeffer have suggested that positional cues confined to individual layers regulate the assembly of local cortical circuits and the formation of thalamocortical projections. One of these wiring molecules is ephrinA5, a ligand for Eph receptor tyrosine kinases. EphrinA5 and Eph receptors exhibit highly dynamic expression patterns in distinct regions of the cortex and thalamus during early and late stages of thalamocortical and cortical circuit formation. In vitro assays suggest that ephrinA5 is a multifunctional wiring molecule for different populations of cortical and thalamic axons. Additionally, the expression patterns of ephrinA5 during cortical development are consistent with this molecule regulating, in alternative ways, specific components of thalamic and cortical connectivity. To test this directly, the organization of thalamocortical projections was examined in mice lacking ephrinA5 gene expression. The anatomical studies in ephrinA5 knockout animals revealed a miswiring of limbic thalamic projections and changes in neocortical circuits that were predicted from the expression pattern and the in vitro analysis of ephrinA5 function. © 2004 Wiley Periodicals, Inc. J Neurobiol 59: 82–94, 2004

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