Biology and pathology of nonmyelinating Schwann cells.
The CNS contains relatively few unmyelinated nerve fibers, and thus benefits from the advantages that are conferred by myelination, including faster conduction velocities, lower energy consumption for impulse transmission, and greater stability of point-to-point connectivity. In the PNS many fibers or regions of fibers the Schwann do not form myelin. Examples include C fibers nociceptors, postganglionic sympathetic fibers, and the Schwann cells associated with motor nerve terminals at neuromuscular junctions. These examples retain a degree of plasticity and a capacity to sprout collaterally that is unusual in myelinated fibers. Nonmyelin-forming Schwann cells, including those associated with uninjured fibers, have the capacity to act as the "first responders" to injury or disease in their neighborhoods.
Griffin
John W
JW
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland.|Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland.|Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Thompson
Wesley J
WJ
Section of Neurobiology, School of Biological Sciences, University of Texas, Austin, Texas.
D000818:Animals; D006801:Humans; D036421:Nerve Fibers, Unmyelinated / Q000502:physiology* / Q000648:ultrastructure; D009416:Nerve Regeneration / Q000502:physiology; D009469:Neuromuscular Junction / Q000502:physiology / Q000648:ultrastructure; D009473:Neuronal Plasticity / Q000502:physiology; D017933:Peripheral Nervous System / Q000166:cytology / Q000502:physiology*; D012583:Schwann Cells / Q000166:cytology / Q000502:physiology*; D017779:Sympathetic Fibers, Postganglionic / Q000502:physiology / Q000648:ultrastructure; D014855:Wallerian Degeneration / Q000503:physiopathology