Elsevier

Brain Research

Volume 549, Issue 2, 24 May 1991, Pages 297-304
Brain Research

Axotomy induces nerve growth factor receptor immunoreactivity in spinal motor neurons

https://doi.org/10.1016/0006-8993(91)90471-7Get rights and content
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Abstract

Expression of the nerve growth factor receptor (NGF-R) mRNA in adult motor neurons is increased by axonal injury. The present study was designed to examine, by immunocytochemistry, the onset, course, and specificity of NGF-R up-regulation following distal or proximal crush of the sciatic nerve. Lesions at both levels induced the appearnce of NGF-R like immunoreactivity in motor neurons beginning on day two postaxotomy. NGF-R-like immunoreactivity was present exclusively in axotomized neurons, as verified by the near complete colocalization of immunoreactive NGF-R with a fluorescent retrograde tracer injected at the crush site. NGF-R expression was closely linked with disconnection of cells from the target; one week after muscle reinnervation, NGF-R immunoreactivity was no longer detectable in animals with distal injuries. These results extend the previous findings of axotomy-induced expression of NGF-R mRNA to the level of the receptor. Furthermore, our observations are consistent with the hypothesis that target-derived factors participate in the regulation of NGF-R gene expression in adult motor neurons.

Keywords

Axon reaction
Muscle
Rat
Regeneration
Sciatic nerve
Trophic factor

Cited by (0)

This work was supported by Grants from the U.S. Public Health Service (NIH AG 05146, AG 03359, NS 20471) as well as funds from The Robert L. & Clara G. Patterson Trust and The Metropolitan Life Foundation. D.L.P. is the recipient of a Javits Neuroscience Investigator Award (NIH NS 10580) and an award from the NIA, Leadership and Excellence in Alzheimer's Disease (AG 07914).

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The authors thank Dr. John W. Griffin for helpful discussions, Mr. William Price and Ms. Judith Van Lare for excellent technical assistance, and Mr. Frank Barksdale for assistance with photography. Dr. Ronald Lindsay provided the monoclonal antibody