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Detection of Neuritic Plaques in Alzheimer's Disease Mouse Model
Published on: July 26, 2011
Plaque complement activation and cognitive loss in Alzheimer's disease
David A Loeffler1, Dianne M Camp, David A Bennett
1Neurology Research Laboratory, William Beaumont Hospital Research Institute, Royal Oak, MI 48073, USA. DLoeffler@beaumont.edu
Journal of Neuroinflammation
|March 13, 2008
Summary
Complement activation occurs on plaques in Alzheimer's disease (AD) and is linked to cognitive decline. Early and late complement markers (iC3b, C9) correlate with plaque load, obscuring direct mediation effects on cognition.
Area of Science:
- Neuroscience
- Immunology
- Pathology
Background:
- Complement activation is elevated in Alzheimer's disease (AD), but its role remains uncertain.
- This study investigates the link between complement activation and cognitive function during AD progression.
Purpose of the Study:
- To determine the relationship between complement activation and cognitive decline in Alzheimer's disease.
- To assess the presence and stage of complement activation on plaques and tangles across cognitive statuses.
Main Methods:
- Immunohistochemical staining (iC3b, C9, Bielschowsky, Gallyas) of brain tissue from normal, mild cognitive impairment, and AD subjects.
- Quantification of plaque counts and correlation with cognitive measures using ANOVA and linear regression.
- Mediation analysis to assess the role of complement markers (iC3b, C9) in the plaque-cognition relationship.
Main Results:
- Complement proteins (iC3b, C9) and plaques were detected in all groups, with significant increases in AD.
- Complement staining was found on diffuse and neuritic plaques, including some diffuse plaques with C9, contrary to prior reports.
- High correlations between complement-stained plaques and Bielschowsky-stained plaques were observed, along with negative correlations to cognitive measures.
Conclusions:
- Both early (iC3b) and late (C9) complement activation are present on neocortical plaques across the cognitive spectrum in AD.
- The strong correlation between complement and amyloid plaques prevented the quantitative assessment of complement's mediating role in cognitive decline.
- Further research, potentially involving animal models or complement inhibitors, is needed to clarify the significance of complement activation in AD pathogenesis.
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