With respect to the major confounders (Figs. S2 and S4), we found a negative correlation between ChAT-ir areas with Braak stage in control subjects (Fig. S2f), and a negative correlation between the GA-ir areas and Braak stage in control and T2DM subjects (Fig. S4f), indicating the NBM neuronal activity declines along the course of cognitive decline. This evidence concerns the gene CHAT and type 2 diabetes mellitus.