PARP1 and Alzheimer disease: Comparing PARP-1 positive nucleoli subcategories (distinct and diffuse staining) showed that the subset of PARP-1 positive nucleoli that had distinct staining was significantly lower in MCI cases compared to both Control and AD cases across the CA (Figure 1(b), Black bars; ANOVA: F2,52 = 11.972 p < .001.