Journal of Neural Transmission

, Volume 109, Issue 3, pp 341–360

The brain insulin signal transduction system and sporadic (type II) Alzheimer disease: an update

  • S. Hoyer

DOI: 10.1007/s007020200028

Cite this article as:
Hoyer, S. J Neural Transm (2002) 109: 341. doi:10.1007/s007020200028


Nosologically, Alzheimer disease may not be considered to be a single disorder in spite of a common clinical phenotype. Only a small proportion of about 5% to 10% of all Alzheimer cases is due to genetic mutations (type I) whereas the great majority of patients was found to be sporadic in origin. It may be assumed that susceptibility genes along with lifestyle risk factors contribute to the causation of the age-related sporadic Alzheimer disease (type II). In this context, the desensitization of the neuronal insulin receptor similar to not-insulin dependent diabetes mellitus may be of pivotal significance. This abnormality along with a reduction in brain insulin concentration is assumed to induce a cascade-like process of disturbances including cellular glucose, acetylcholine, cholesterol, and ATP associated with abnormalities in membrane pathology and the formation of both amyloidogenic derivatives and hyperphosphorylated tau protein. Sporadic Alzheimer disease may, thus, be considered to be the brain type of diabetes mellitus II. Experimental evidence is provided and discussed.

Keywords: Braininsulininsulin receptorsporadic Alzheimer disease.

Copyright information

© Springer-Verlag Wien 2002

Authors and Affiliations

  • S. Hoyer
    • 1
  1. 1.Department of Pathochemistry and General Neurochemistry, University of Heidelberg, Federal Republic of GermanyDE