Characterization of neuronal dystrophy induced by fibrillar amyloid beta: implications for Alzheimer's disease

Neuroscience. 2002;114(1):265-73. doi: 10.1016/s0306-4522(02)00241-5.

Abstract

Amyloid deposition, neuronal dystrophy and synaptic loss are characteristic pathological features of Alzheimer's disease (AD). We have used cortical neuronal cultures to assess the dystrophic effect of fibrillar amyloid beta (Abeta) and its relationship with neurotoxicity and synaptic loss. Treatment with fibrillar Abeta led to the development of neuritic dystrophy in the majority of the neurons present in the culture. Morphometric analysis and viability assays showed that neuronal dystrophy appeared significantly earlier and at lower Abeta concentrations than neurotoxicity, suggesting that both effects are generated independently by different cellular mechanisms. The development of dystrophic features required Abeta fibril formation and did not depend on the presence of the RHDS adhesive domain in the sequence of Abeta. Finally, a dramatic reduction in the density of synaptophysin immunoreactivity was closely associated with dystrophic changes in viable neurons. These results suggest that aberrant plastic changes and loss of synaptic integrity induced by fibrillar Abeta may play a significant role in the development of AD pathology.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alzheimer Disease / metabolism*
  • Alzheimer Disease / pathology
  • Alzheimer Disease / physiopathology
  • Amyloid beta-Peptides / metabolism
  • Amyloid beta-Peptides / toxicity*
  • Animals
  • Cells, Cultured
  • Cerebral Cortex / metabolism*
  • Cerebral Cortex / pathology
  • Cerebral Cortex / physiopathology
  • Dendrites / drug effects
  • Dendrites / metabolism
  • Dendrites / pathology
  • Down-Regulation / drug effects
  • Down-Regulation / physiology
  • Fetus
  • Immunohistochemistry
  • Nerve Degeneration / chemically induced
  • Nerve Degeneration / pathology
  • Nerve Degeneration / physiopathology*
  • Neural Pathways / drug effects
  • Neural Pathways / metabolism
  • Neural Pathways / pathology
  • Neurites / drug effects
  • Neurites / metabolism
  • Neurites / pathology
  • Neurofibrils / drug effects
  • Neurofibrils / metabolism*
  • Neurofibrils / pathology
  • Neuronal Plasticity / drug effects
  • Neuronal Plasticity / physiology
  • Neurons / drug effects
  • Neurons / metabolism*
  • Neurons / pathology
  • Protein Structure, Tertiary / drug effects
  • Protein Structure, Tertiary / physiology
  • Rats
  • Synapses / drug effects
  • Synapses / metabolism
  • Synapses / pathology
  • Synaptophysin / drug effects
  • Synaptophysin / metabolism

Substances

  • Amyloid beta-Peptides
  • Synaptophysin