(A) RbAp48 gene expression over life span in (a) the DG showing a decline (β = −0.77, P = 0.026) and (b) the EC (β = 0.07, P = 0.87) showing no decline. (c) DG/EC ratio of RbAp48 declines with age (β = −0.94, P = 0.0005) (n = 8). (B) RbAp48 protein in separate group of brains (n = 10). RbAp48 protein levels decline over the life span (a) in the DG (β = −0.72, P = 0.02), but not (b) in the EC (β = 0.13, P = 0.71). (c) DG protein expression normalized to EC protein expression. In (A) and (B), each data point corresponds to one human subject and microarray experiment. (C) Human subjects used in the studies. (D) Representative Western blot showing RbAp48 levels in a young and an old sample. SUB, subiculum; ACT, actin (control; data from DG are shown).