Fig. 8

Relationship between Aβ plaques and AxDs formation and development. (a, b), Maximum projection of images (120 images, z = 0.3 μm) showing the presence of a large AxD (blue arrow) and a small AxD (red arrow) (GFP, green) close to a large plaque stained with Methoxy-X04 (blue) (b). Note that the larger AxD starts to develop around day 130 (animal age). (c, d), Maximum projection of images (120 images, z = 0.3 μm) showing the presence of smaller AxDs (red arrows) (GFP, green) close to a small Aβ plaque stained with Methoxy-X04 (blue) (d). These two smaller AxDs appear around day 232 (animal age). (c). Panoramic images that show the regions in panels a - d are in the Additional file 6. (e), Maximum projection of images (134 images, z = 0.3 μm) showing GFP-expressing neurites and Aβ plaques stained with Methoxy-X04 (blue). There is an axon with two AxDs: one small AxD that is not associated with Aβ plaques (arrowhead), and another which is close to an Aβ plaque stained with Methoxy-X04 (arrow). The days shown refer to the animal age (the imaging began on day 100 of the animal lifetime). (f), Graph showing the percentage of the total number of AxDs (n = 47) that are present over time. Days in X correspond to the bin center (bin width = 20 days). (g), Correlation (Spearman r: −0.4711, p = 0.0022) between the maximum AxD volume and the day of AxD appearance, indicating that larger AxDs develop earlier than smaller AxDs in the animal lifetime. (h), Correlation (Spearman r: 0.6173, p < 0.0001) between the maximum volume that an AxD reaches and the maximum volume of the Aβ plaque it is associated with. Large AxDs are present only around large Aβ plaques. Scale bar (in e): 25.1 μm in a-d; 28.4 μm in e