Potential roles of Alzheimer precursor protein A4 and beta-amyloid in survival and function of aged spinal motor neurons after axonal injury

J Neurosci Res. 2003 Aug 15;73(4):557-64. doi: 10.1002/jnr.10667.

Abstract

To study the potential role of Alzheimer precursor protein A4 (APP) and beta-amyloid (A/beta) on aging motor neuron survival, expression of APP, A/beta, and choline acetyltransferase (ChaT) were investigated in aged rats after either distal axotomy or root avulsion injury. Approximately 45% in number of total aged spinal motor neuron were normally APP-positive. A/beta-positive neurites were observed normally in the spinal ventral horn of aged rats. After distal axotomy, without apparent neurodegeneration such as cell loss and decreased ChaT-immunoreactivity, increased levels of APP expression were observed in the spinal cords of aged rats post-injury. In contrast, after avulsion, expression of APP and A/beta were downregulated in the spinal ventral horn of aged rats, and marked loss of spinal motor neurons and downregulated ChaT expression were observed. Our data indicate that APP and A/beta might play beneficial roles in neuronal survival of aged spinal motor neurons after axonal injury.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / pathology*
  • Amyloid beta-Peptides / pharmacology*
  • Amyloid beta-Protein Precursor / pharmacology*
  • Animals
  • Axotomy / methods
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • Choline O-Acetyltransferase / metabolism
  • Disease Models, Animal
  • Immunohistochemistry / methods
  • Male
  • Motor Neurons / drug effects*
  • Motor Neurons / pathology
  • Radiculopathy / metabolism
  • Radiculopathy / pathology
  • Rats
  • Rats, Sprague-Dawley
  • Spinal Cord / metabolism
  • Spinal Cord / pathology
  • Spinal Injuries / pathology*
  • Time Factors

Substances

  • Amyloid beta-Peptides
  • Amyloid beta-Protein Precursor
  • Choline O-Acetyltransferase