Axonal Ensheathment and Septate Junction Formation in the Peripheral Nervous System of Drosophila
| Autor: | Manzoor A. Bhat, Anilkumar M. Pillai, Raehum Paik, Jingjun Li, Swati Banerjee |
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| Jazyk: | angličtina |
| Rok vydání: | 2006 |
| Předmět: |
Nervous system
Action potential Cell Adhesion Molecules Neuronal Recombinant Fusion Proteins Green Fluorescent Proteins tau Proteins Septate junctions Cell Communication Biology Microscopy Electron Transmission Contactins Ranvier's Nodes Cell Adhesion medicine Animals Drosophila Proteins Peripheral Nerves Cell adhesion Blood-Nerve Barrier General Neuroscience Cell Membrane Articles Embryonic stem cell Axons Drosophila melanogaster medicine.anatomical_structure nervous system Peripheral nervous system Mutation Ultrastructure Neuroglia Neuroscience |
| DOI: | 10.17615/wbdw-qj83 |
| Popis: | Axonal insulation is critical for efficient action potential propagation and normal functioning of the nervous system. InDrosophila, the underlying basis of nerve ensheathment is the axonal insulation by glial cells and the establishment of septate junctions (SJs) between glial cell membranes. However, the details of the cellular and molecular mechanisms underlying axonal insulation and SJ formation are still obscure. Here, we report the characterization of axonal insulation in theDrosophilaperipheral nervous system (PNS). Targeted expression oftau-green fluorescent proteinin the glial cells and ultrastructural analysis of the peripheral nerves allowed us to visualize the glial ensheathment of axons. We show that individual or a group of axons are ensheathed by inner glial processes, which in turn are ensheathed by the outer perineurial glial cells. SJs are formed between the inner and outer glial membranes. We also show that Neurexin IV, Contactin, and Neuroglian are coexpressed in the peripheral glial membranes and that these proteins exist as a complex in theDrosophilanervous system. Mutations inneurexin IV,contactin, andneuroglianresult in the disruption of blood–nerve barrier function in the PNS, and ultrastructural analyses of the mutant embryonic peripheral nerves show loss of glial SJs. Interestingly, the murine homologs of Neurexin IV, Contactin, and Neuroglian are expressed at the paranodal SJs and play a key role in axon-glial interactions of myelinated axons. Together, our data suggest that the molecular machinery underlying axonal insulation and axon-glial interactions may be conserved across species. |
| Databáze: | OpenAIRE |
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