Fig. 3

Age-related increases in IL-1β appear to be restricted to the hippocampus, whereas age-related increases in IL-6 are noted throughout the brain. A Across sexes, middle-aged, and old mice expressed higher levels of IL-6 protein (migrating at ~21 kDa) relative to young mice in the dorsal hippocampus. The fact that the effect of age occurs across sexes is indicated by the significance marker (i.e., * or #) being placed above a bar that extends across the male and female histograms (see Table 1). B) IL-1β (migrating as a doublet at ~25 kDa) also appears to be upregulated with age across sexes in the dorsal hippocampus as old mice showed stronger signals in both the upper and lower bands relative to young mice. C IL-6 was significantly elevated in the prefrontal cortex of old mice relative to young mice; however, D IL-1β expression did not change with age in the prefrontal cortex. A similar pattern was observed in striatum, with E old mice expressing more IL-6 than young mice but F not more IL-1β. G In the cerebellum, both middle-aged and old mice showed higher levels of IL-6 relative to young mice. H In contrast, IL-1β—which migrated as a single-thick band in the cerebellum—did not change with age. Data expressed as mean ±SEM. Brightness and contrast of blots and Ponceau stain (PS) images adjusted for graphical clarity. Effect of age across sexes: *vs young, P=0.005 to <0.001; #vs young and middle, P<0.001; rank sum test of sex within old: @vs. male, P=0.044. LB—lower band, UB—upper band, Y—young, M—middle aged, O—old