Fig. 3.

Differential localization patterns of complexins I (CPX1) and II (CPX2) versus SNARE proteins within β-amyloid (Aβ) plaques in the subiculum of participants with variable degrees of Alzheimer’s disease pathology. a, c, e, g Single- or merged-channel confocal images from triple co-immunolabeled sections with the antibodies against phosphotau (clone AT8), Aβ (clone 6F/3D) and CPX1 (a), CPX2 (c), vesicle-associated membrane protein (VAMP) (e), or SNAP-25 (S25) (g). In merged images, colors were arbitrarily assigned to maximize overlap visualization, and correspond to the colors of the labels in the single-channel images on the left. Areas occupied by neuritic plaques (as visualized by Aβ immunostaining) were grossly outlined in all channels. Scale bars: 20 μm. b, d, f, h Semi-quantitative colocalization data evaluating the number of overlapping pixels between phosphotau (yellow bars) or Aβ (magenta bars), and CPX1 (b), CPX2 (d), VAMP (f), or SNAP-25 (h), divided by the total number of pixels of the presynaptic proteins with an intensity over an unbiased threshold, and within the outlined areas. Bars represent mean ± standard deviation of all n = 7 MAP participants. Images next to the bar plots are ImageJ-generated bitmap outputs from the colocalization analyses of the image outlines on the left, representing the overlapping pixel intensities between phosphotau (yellow bitmaps) or Aβ (magenta bitmaps), and the corresponding presynaptic target.