Local modulation of neurofilament phosphorylation, axonal caliber, and slow axonal transport by myelinating Schwann cells.
Studies in Trembler and control mice demonstrated that myelinating Schwann cells exert a profound influence on axons. Extensive contacts between myelin and axons have been considered structural. However, demyelination decreases neurofilament phosphorylation, slow axonal transport, and axonal diameter, as well as significantly increasing neurofilament density. In control sciatic nerves with grafted Trembler nerve segments, these changes were spatially restricted: they were confined to axon segments without normal myelination. Adjacent regions of the same axons had normal diameters, neurofilament phosphorylation, cytoskeletal organization, and axonal transport rates. Close intercellular contacts between myelinating Schwann cells and axons modulate a kinase-phosphatase system acting on neurofilaments and possibly other substrates. Myelination by Schwann cells sculpts the axon-altering functional architecture, electrical properties, and neuronal morphologies.
Department of Cell Biology and Neuroscience, University of Texas Southwestern Medical Center, Dallas 75235.
S M
SM
de Waegh
V M
VM
Lee
S T
ST
Brady
D000818:Animals; D000911:Antibodies, Monoclonal; D001370:Axonal Transport; D001369:Axons / Q000378:metabolism* / Q000648:ultrastructure; D007382:Intermediate Filaments / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D008810:Mice, Inbred C57BL; D008818:Mice, Neurologic Mutants; D009186:Myelin Sheath / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism; D012583:Schwann Cells / Q000378:metabolism*; D012584:Sciatic Nerve / Q000378:metabolism* / Q000648:ultrastructure
D000911:Antibodies, Monoclonal; D010770:Phosphotransferases; D010744:Phosphoric Monoester Hydrolases