In vivo imaging of axonal transport using MRI: aging and Alzheimer's disease

Eur J Nucl Med Mol Imaging. 2008 Mar;35 Suppl 1:S89-92. doi: 10.1007/s00259-007-0707-8.

Abstract

Purpose: MRI using manganese as a trans-synaptic axonal tracing agent can unveil dynamics of axonal transport in living subjects. We use this technology to test the hypotheses if impaired axonal transport is a significant pathophysiological process in aging and early Alzheimer's disease (AD) and in part accounting for "selective vulnerability" of projection neurons in AD.

Methods: To allow quantitative assessment of axonal transport in vivo, we developed voxel-based statistical mapping technology as well as a tracer kinetic modeling method based on mass transport for manganese-enhanced MRI to estimate axonal transport rates in aging rats and AD transgenic mice.

Results: These techniques demonstrated manganese-enhanced signal changes in axonal projections of the olfactory tract and decreased axonal transport rates in rodent models of aging and AD.

Conclusion: Altered axonal transport may be a critical pathophysiological process in aging and AD. Manganese-enhanced MRI provides exciting opportunities for the investigations of altered axonal transport in AD and related disorders.

Publication types

  • Review

MeSH terms

  • Aging / pathology*
  • Alzheimer Disease / pathology*
  • Animals
  • Axons / pathology*
  • Brain / pathology*
  • Contrast Media
  • Image Enhancement / methods*
  • Magnetic Resonance Imaging / methods*
  • Manganese*
  • Mice
  • Neural Pathways / pathology
  • Rats

Substances

  • Contrast Media
  • Manganese