Contributions
Abstract: P453
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Neurobiology
The fast and reliable propagation of action potentials along myelinated fibers relies on the clustering of voltage-gated sodium channels (Nav) at the nodes of Ranvier. Our recent study uncovered the influence of oligodendroglial secreted factors for nodal protein clustering before myelination (i.e. prenodes) on hippocampal interneurons and extended to electrophysiological characterization and in vivo relevance (Freeman et al., 2015). We further characterized the oligodendrocyte-conditioned medium (OCM) activity and found that addition of a combination of recombinant cell adhesion molecule and extracellular matrix proteins on purified neuron culture is sufficient to induce Nav clustering in the absence of oligodendrocytes. Furthermore, inhibition of the protein activity in the OCM, using an immunodepletion approach and knock out models, reduces its clustering activity. Altogether this suggests that early events of nodal protein clustering result in a complex interplay of cell adhesion molecules and extracellular matrix proteins. Moreover, to further characterize the intrinsic neuronal properties within the cells that develops nodes prior to myelination, we analyzed their electrophysiological properties. We also use a gene expression analysis approach to compare gene expression in hippocampal neurons with and without prenodes. This could allow for identification of specific roles for oligodendrocytes or their precursors in the developing nervous system and interactions that mediate myelination of interneurons.
Disclosure: Anne-Laure Dubessy : nothing to disclose
Elisa Mazuir : nothing to disclose
Louis Richevaux : nothing to disclose
Quentin Rappeneau : nothing to disclose
Sokounthie Ou : nothing to disclose
Anne Desmazières : nothing to disclose
Bernard Zalc : nothing to disclose
Desdemona Fricker : nothing to disclose
Barbara Ranscht : nothing to disclose
Catherine Lubetzki : nothing to disclose
Nathalie Sol-Foulon : nothing to disclose
Abstract: P453
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Neurobiology
The fast and reliable propagation of action potentials along myelinated fibers relies on the clustering of voltage-gated sodium channels (Nav) at the nodes of Ranvier. Our recent study uncovered the influence of oligodendroglial secreted factors for nodal protein clustering before myelination (i.e. prenodes) on hippocampal interneurons and extended to electrophysiological characterization and in vivo relevance (Freeman et al., 2015). We further characterized the oligodendrocyte-conditioned medium (OCM) activity and found that addition of a combination of recombinant cell adhesion molecule and extracellular matrix proteins on purified neuron culture is sufficient to induce Nav clustering in the absence of oligodendrocytes. Furthermore, inhibition of the protein activity in the OCM, using an immunodepletion approach and knock out models, reduces its clustering activity. Altogether this suggests that early events of nodal protein clustering result in a complex interplay of cell adhesion molecules and extracellular matrix proteins. Moreover, to further characterize the intrinsic neuronal properties within the cells that develops nodes prior to myelination, we analyzed their electrophysiological properties. We also use a gene expression analysis approach to compare gene expression in hippocampal neurons with and without prenodes. This could allow for identification of specific roles for oligodendrocytes or their precursors in the developing nervous system and interactions that mediate myelination of interneurons.
Disclosure: Anne-Laure Dubessy : nothing to disclose
Elisa Mazuir : nothing to disclose
Louis Richevaux : nothing to disclose
Quentin Rappeneau : nothing to disclose
Sokounthie Ou : nothing to disclose
Anne Desmazières : nothing to disclose
Bernard Zalc : nothing to disclose
Desdemona Fricker : nothing to disclose
Barbara Ranscht : nothing to disclose
Catherine Lubetzki : nothing to disclose
Nathalie Sol-Foulon : nothing to disclose