Intrahippocampal RGFP136 infusions increases histone acetylation. Images on left are 4×, and 20× magnifications of the regions boxed in white are on the right. Histograms depict quantification of optical density as a percentage of vehicle. A, HDAC3 immunoreactivity is unaltered in area of infusion 2 h after RGFP136 treatment compared with vehicle. B, Representative images show HDAC2 immunoreactivity in dorsal hippocampus is also unchanged by drug treatment. C, However, HDAC4 nuclear immunoreactivity is decreased in the region of the RGFP136 infusion. *p < 0.05. D, Furthermore, acetylation at H4K8 is increased in RGFP136-infused mice compared with those treated with vehicle. *p < 0.05.