Plaque-associated features accumulate over the clinical course of AD. A–D: Plots represent the KS difference between the distribution histogram from pairs of subjects against their difference in symptom duration. Note that the larger the difference in symptom duration between two subjects, the larger the difference in their distribution histograms for SMI312+ dystrophic neurites (A), GFAP+ astrocytes (B), and CD68+ microglia (D) per plaque, indicating accrual over the clinical course of the disease. This association was, however, not significant for IBA1+ microglia per plaque (C). n = 40 AD subjects and 9 CTRL subjects (8 CTRL for SMI312+ dystrophic neurites). AD, Alzheimer disease; CTRL, control; KS, Kolmogorov-Smirnov.