Fig. 4.

Oligomeric Aβ associates with PSDs. (A) Projection of images of array sections (500-nm total thickness) that have been processed by using the watershed analysis program (thresholded and puncta present in only one section excluded) show postsynaptic densities (green) and oligomeric Aβ (NAB61; red). (B) Higher-resolution projections from within the halo of oligomeric Aβ surrounding a plaque further than 50 μm from a plaque in APP/PS1 transgenic mouse cortex and a volume from nontransgenic cortex show that oligomeric Aβ staining is present at some postsynaptic densities (yellow). (C) Z-projections of raw images from an array of a mouse transgenic for YFP (stained green in C) and APP/PS1 demonstrate that NAB61 puncta (red) contact dendritic spines (arrows point to spine heads, yellow shows colocalization) both in the halo of oligomeric Aβ surrounding a plaque and distant from plaques. (Scale bars: A and C, 5 μm; B, 1 μm.