Full- versus Sub-Regional Quantification of Amyloid-Beta Load on Mouse Brain Sections

Extracellular accumulation of amyloid-beta (A beta) plaques is one of the major pathological hallmarks of Alzheimer's disease (AD), and is the target of the only FDA-approved disease-modifying treatment for AD. Accordingly, the use of transgenic mouse models that overexpress the amyloid precursor protein and thereby accumulate cerebral A beta plaques are widely used to model human AD in mice. Therefore, immunoassays, including enzyme-linked immunosorbent assay (ELISA) and immunostaining, commonly measure the A beta load in brain tissues derived from AD transgenic mice. Though the methods for A beta detection and quantification have been well established and documented, the impact of the size of the region of interest selected in the brain tissue on A beta load measurements following immunostaining has not been reported. Therefore, the current protocol aimed to compare the A beta load measurements across the full- and sub-regions of interest using an image analysis software. The steps involved in brain tissue preparation, free-floating brain section immunostaining, imaging, and quantification of A beta load in full- versus sub-regions of interest are described using brain sections derived from 13-month-old APP/PS1 double transgenic male mice. The current protocol and the results provide valuable information about the impact of the size of the region of interest on A beta-positive area quantification, and show a strong correlation between the A beta-positive area obtained using the full- and sub-regions of interest analyses for brain sections derived from 13month-old male APP/PS1 mice that show widespread A beta deposition.

Automated summary

This study aims to compare the measurements of Aβ load in full and sub-regions of interest using image analysis software, and provides valuable information and results.