Related Experiment Videos
Diffuse plaques do not accentuate synapse loss in Alzheimer's disease
E Masliah1, R D Terry, M Mallory
1Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla 92093.
The American Journal of Pathology
|December 1, 1990
Summary
Synapse loss in Alzheimer's disease (AD) is more pronounced in immature and mature plaques. This suggests neurodegeneration may precede amyloid beta protein deposition in AD pathogenesis.
Area of Science:
- Neuroscience
- Neuropathology
- Cell Biology
Background:
- Alzheimer's disease (AD) is characterized by amyloid beta protein plaques.
- Synaptic loss is a hallmark of AD neurodegeneration.
- The precise sequence of pathological events in AD remains debated.
Purpose of the Study:
- To investigate the relationship between amyloid beta plaques and synaptic density in Alzheimer's disease.
- To determine if synapse loss occurs before or after amyloid beta deposition.
Main Methods:
- Utilized laser confocal imaging for high-resolution examination of brain tissue.
- Employed double immunolabeling to detect amyloid beta protein and synaptophysin (a presynaptic marker).
- Analyzed vibratome sections of cortical neuropil from AD patients and controls.
Main Results:
- Overall synaptic density was reduced in the AD cortex compared to controls.
- Synapse loss was not significantly greater within diffuse plaques compared to surrounding tissue.
- Synapse loss was markedly accentuated within both immature and mature amyloid plaques.
Conclusions:
- Synaptic degeneration may be an early event in Alzheimer's disease pathogenesis.
- The findings challenge the view that amyloid beta deposition is the primary initiating event.
- Neurodegeneration, indicated by synapse loss, might precede significant amyloid plaque formation in AD.