Increased CD68 immunoreactivity in the cerebral cortex and VPM/VPL of aged PGRN-deficient mice. A, CD68-immunostained images of the cerebral cortex (upper images) and VPM/VPL (lower images) of 10- and 90-week-old wild-type (WT) and PGRN-deficient (KO) mice (scale bar = 200 μm). B, High-power image of CD68 immunostaining of the VPM/VPL of 90-week-old KO mice (scale bar = 10 μm). C, D, CD68-positive area in the cerebral cortex ( C ) and VPM/VPL ( D ) of 10- and 90-week-old WT and KO mice. The data are presented as the change relative to the level in 10-week-old WT mice. Values are the mean ± SEM (n = 5 for each group). Values having a different superscript are significantly different (P < 0.05, Tukey-Kramer test).