Fig. 2.

The number of IBA1⁺ microglia and cathepsin B⁺ cells is increased in EOAD and AD-DS compared with healthy ageing but no change in the proportion of cathepsin B⁺ microglia occurs. a–c Representative images of IBA1 (cyan), cathepsin B (magenta) and DAPI-nucleus (blue) stained cells, and colocalised IBA1 and cathepsin B staining in human temporal cortex from individuals with a healthy ageing, b EOAD or c AD-DS. d The number of IBA1⁺ microglia/mm² was significantly altered by the type of case (ANOVA F(2,19) = 6.527, p = 0.007); significantly more cells were observed in both cases of EOAD and AD-DS compared with healthy ageing (pairwise comparisons with Bonferroni correction EOAD p = 0.005, AD-DS p = 0.028) but no difference was observed between EOAD and AD-DS. e The number of cathepsin B⁺ cells/mm² was significantly altered by the type of case (ANOVA F(2,19) = 13.379, p < 0.001); significantly more cells were observed in both cases of EOAD and AD-DS compared with healthy ageing controls (pairwise comparisons with Bonferroni correction EOAD p = 0.002, AD-DS p < 0.001) but no difference was observed between EOAD and AD-DS. f The proportion of total cathepsin B staining that colocalised with IBA1⁺ microglia was not altered by case type (ANOVA F(2,19) = 3.446, p = 0.053). g The proportion of IBA1 microglia that were also positive for cathepsin B was not altered by case type (ANOVA F(2,19) = 1.493, p = 0.250). *p < 0.05, **p < 0.01 and ***p < 0.001