Levels of Aβ in brain tissue of 1-day-old APP, PS1, APP/PS1 and NTG mice.

<p><b>A.</b> Levels of Aβ in brain tissue were determined using monoclonal antibody 4G8 that recognizes human and mouse abnormally processed Aβ isoforms and precursor forms (<b>a–d</b>). Scale bar, 200 µm. Levels of Aβ in CA1 Hip pyramidal neurons detected with 4G8 antibody (<b>e–h</b>) or antibody A11 that recognizes Aβ oligomers (<b>i–l</b>). Scale bar, 20 µm. <b>B.</b> Densitometry measurements of immunostaining produced by 4G8 and A11 antibodies in a–l. The lighter staining of the NTG brain resulted in ratios closer to 1, indicating the stained tissue was almost as bright as the bare slide and therefore, had lower Aβ immunoreactivity. As the Aβ immunoreactivity increases, the normalized intensity ratios decrease, with the lowest values observed in the APP/PS1 mouse brain because the tissue becomes darker and closer to black. Data is expressed as mean ± SEM. Blue – Ctx 4G8; red – Hip 4G8; green – Ctx A11; purple – Hip A11. * <0.01. Ab – antibody.