Regulation of aberrant neurofilament phosphorylation in neuronal perikarya. IV. Evidence for the involvement of two signals.
Axonal regeneration over long distances is dependent upon events occurring both in the distal stump and in the neuronal cell body. Little is known concerning how events in the distal stump influence the cell body response to injury, or the axon reaction. In the present study, we examined this relationship for one component of the axon reaction (i.e. aberrant neurofilament (NF) phosphorylation) in the C57BL/Ola (Ola) mouse mutant, a model which exhibits delayed Wallerian degeneration (up to 3 weeks) and retarded regeneration of sensory neurons. Non-axotomized normal (C57/6J/BL) and Ola mice demonstrated modest immunostaining to phosphorylated NF (pNF) epitopes (using monoclonal antibody 06-17) in some (11%) L4 dorsal root ganglion (DRG) neuronal cell bodies. In normal mice, modest to intense immunoreactivity was present in 43% of DRG neurons at 1 week following a sciatic nerve crush (axotomy). The intensity and extent of staining declined with reinnervation, being reduced slightly at 2 weeks and more notably by 3 weeks following axotomy. In Ola mice, the intensity and extent (43%) of staining were not different from normal axotomized mice at 1 week following axotomy. However, the intensity was less and the extent of staining reduced by 28% at 2 weeks following axotomy. By 3 weeks, staining levels were again increased, being similar to that observed in Ola and normal mice at 1 week following axotomy.(ABSTRACT TRUNCATED AT 250 WORDS)
Gold
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Center for Research on Occupational and Environmental Toxicology, Oregon Health Sciences University, Portland 97204-3098.
Storm-Dickerson
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Austin
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D000818:Animals; D001369:Axons / Q000502:physiology; D000939:Epitopes; D007124:Immunoenzyme Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D008818:Mice, Neurologic Mutants; D009454:Neurofibrils / Q000378:metabolism*; D009475:Neurons, Afferent / Q000378:metabolism*; D010766:Phosphorylation; D015398:Signal Transduction / Q000502:physiology*; D014855:Wallerian Degeneration / Q000502:physiology*
D000939:Epitopes