FKBP1b counters the age-related decrease in hippocampal MAP2 protein expression. FKBP1b counters the age-related decrease in hippocampal MAP2 protein expression. Top, Semiquantitative measures of MAP2 IHC staining densities plotted as a function of treatment. Statistical analysis revealed a significant effect (p = 0.0015; one-way ANOVA) with a significant decrease from YC to AC that was countered by ST FKPB1b (**p ≤ 0.01, ***p ≤ 0.001, †n.s. trend p = 0.06; post hoc Fisher's pLSD vs AC). Bottom, Immunostaining for hippocampal MAP2 expression. Representative photomicrographs are shown from YC (rectangle defines region of quantitation; A), AC (B), aged ST FKBP1b (C), and aged LT FKBP1b (D). Scale bar, 500 μm. John C. Gant et al. J. Neurosci. 2018;38:1030-1041 ©2018 by Society for Neuroscience