Denervation of the motor endplate results in the rapid expression by terminal Schwann cells of the growth-associated protein GAP-43
| Autor: | M.L. Reynolds, Clifford J. Woolf, Irwin N, M.S. Chong, P.C. Emson, Larry I. Benowitz |
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| Rok vydání: | 1992 |
| Předmět: |
Schwann cell
Nerve Tissue Proteins Motor Endplate Neuromuscular junction Rats Sprague-Dawley Perisynaptic schwann cells GAP-43 Protein medicine Animals Gap-43 protein Axon Denervation Membrane Glycoproteins biology General Neuroscience Articles Immunohistochemistry Muscle Denervation Cell biology Rats medicine.anatomical_structure nervous system biology.protein Mesaxon Schwann Cells Neuroscience |
| Zdroj: | The Journal of neuroscience : the official journal of the Society for Neuroscience. 12(10) |
| ISSN: | 0270-6474 |
| Popis: | Developing and regenerating neurons express high levels of the growth- associated phosphoprotein GAP-43. This membrane protein is not confined to neurons, however, as a number of studies have demonstrated GAP-43 immunoreactivity in central and peripheral glia in vitro and in vivo. We have found that the Schwann cells overlying the terminal motor axon at adult rat skeletal muscle endplates, and the motor axons themselves, are normally not GAP-43 immunoreactive. Within 24 hr of denervation, however, the terminal Schwann cells are positive for a GAP-43 mRNA in situ hybridization signal and are GAP-43 immunoreactive. The immunoreactive GAP-43 cells possess elaborate processes that branch from the endplate region into the perisynaptic zone and stain with defined Schwann cell markers: the calcium binding protein S100 and the low-affinity NGF receptor (NGFr), but not with a fibroblast marker, Thy- 1. Reinnervating motor axons are GAP-43 positive, with an appearance quite different from the GAP-43-positive Schwann cells. The reappearance of nerve endings at the motor endplate is followed by the disappearance of GAP-43 labeling in the Schwann cells and of a retraction of their processes. GAP-43 expression in Schwann cells is therefore state dependent, apparently regulated by neural contact. This protein, which is associated in neurons with neurite formation, may participate in the elaboration of processes by Schwann cells when their contact with axons is disrupted. |
| Databáze: | OpenAIRE |
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