Physiological roles for amyloid beta peptides

J Physiol. 2006 Aug 15;575(Pt 1):5-10. doi: 10.1113/jphysiol.2006.111203. Epub 2006 Jun 29.


Alzheimer's disease is recognized post mortem by the presence of extracellular senile plaques, made primarily of aggregation of amyloid beta peptide (Abeta). This peptide has consequently been regarded as the principal toxic factor in the neurodegeneration of Alzheimer's disease. As such, intense research effort has been directed at determining its source, activity and fate, primarily with a view to preventing its formation or its biological activity, or promoting its degradation. Clearly, much progress has been made concerning its formation by proteolytic processing of the amyloid precursor protein, and its degradation by enzymes such as neprilysin and insulin degrading enzyme. The activities of Abeta, however, are numerous and yet to be fully elucidated. What is currently emerging from such studies is a diffuse but steadily growing body of data that suggests Abeta has important physiological functions and, further, that it should only be regarded as toxic when its production and degradation are imbalanced. Here, we review these data and suggest that physiological levels of Abeta have important physiological roles, and may even be crucial for neuronal cell survival. Thus, the view of Abeta being a purely toxic peptide requires re-evaluation.

Publication types

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

MeSH terms

  • Amyloid beta-Peptides / metabolism
  • Amyloid beta-Peptides / physiology*
  • Amyloid beta-Protein Precursor / metabolism*
  • Animals
  • Calcium Channels, L-Type / metabolism
  • Cell Survival
  • Central Nervous System / cytology
  • Central Nervous System / metabolism
  • Central Nervous System / physiology*
  • Humans
  • Hypoxia / metabolism
  • Neurons / cytology
  • Neurons / metabolism
  • Neurons / physiology
  • Potassium Channels / metabolism
  • Protein Processing, Post-Translational*
  • Synaptic Transmission


  • Amyloid beta-Peptides
  • Amyloid beta-Protein Precursor
  • Calcium Channels, L-Type
  • Potassium Channels