Figure 2. Plots of individual basal forebrain cholinergic system and hippocampus grey matter volumes against age.

Individual left and right hemispheric hippocampus and basal forebrain cholinergic system (BFCS) grey matter (GM) volumes of the healthy cohort are plotted against age (circles). Linear and quadratic trends are shown by continuous and interrupted lines, respectively. The plots indicate stable (or even increasing) hippocampus GM volumes until middle-age and subsequent non-linear decline at advanced age. On the other hand, decline of BFCS GM volumes can be seen from early adulthood on and aggravates at advanced age.