Shift from fibrillar to nonfibrillar Aß deposits in the neocortex of subjects with Alzheimer disease Academic Article uri icon

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  • A morphometric study of amyloid-beta-positive plaques in the neocortex of eight non-demented people from 68 to 82 years of age and 17 subjects with late-stage Alzheimer disease (GDS stage 7/FAST stages 7a-f) from 73 to 93 years of age shows a shift from prevalence of fibrillar plaques to prevalence of nonfibrillar plaques. In the aged, non-demented subjects, about 4/mm^2 plaques are detectable in the neocortex, and the majority are fibrillar plaques. Specifically, 64% found to be classical fibrillar and Thioflavin-S-positive bright primitive plaques. A lower percentage of pale primitive plaques (35%) relatively small proportion of plaques that are poor in thioflavin S-positive fibrils. The numerical density of plaques in the severe stage of AD increases to about 41/mm^2. Severely demented subjects appear to maintain an active process of fibrillar plaque formation. This is reflected in the presence of 3% bright primitive plaques. Severely demented subjects also manifest plaque degradation, reflected in the presence of 22% and 48% percentages of classical fibrillar plaques in non-demented subjects and in the end stage of disease suggest that once activated, the process of fibrillar plaque formation persists at a somewhat stable rate during the whole course of brain amyloidosis.


  • Wegiel, Jerzy
  • Bobinski, Maciej
  • Tarnawski, Michal
  • Dziewiatkowski, Jerzy
  • Popovitch, Eirene
  • Bobinski, Margaret
  • Lach, Boleslaw
  • Reisberg, Barry
  • Miller, Douglas C
  • de Santi, Susan
  • de Leon, Mony J

publication date

  • March 5, 2001