Increased lipofuscin accumulation in the VPM/VPL of aged PGRN-deficient mice. A, Autofluorescence images of the cerebral cortex, hippocampus, and VPM/VPL of 90-week-old wild-type (WT) and PGRN-deficient (KO) mice (scale bar = 200 μm). B, Autofluorescence (AF) area of the cerebral cortex, CA3 of the hippocampus, and VPM/VPL of 90-week-old WT and KO mice. Values are the mean ± SEM (n = 5 for each group, *P < 0.05, unpaired t-test). C, D, E, F, Hematoxylin-stained ( C ), Schmorl-stained ( D ), periodic acid-Schiff (PAS)-stained ( E ), and Oil-red-O-stained ( F ) images of the VPM/VPL of 90-week-old KO mice (scale bar = 20 μm). G, Images double-stained with Sudan black B and CD11b in the VPM/VPL of 90-week-old KO mice (scale bar = 10 μm). Black and white arrows indicate Sudan black B-positive and CD11b-positive cells, respectively.