Histone Modifications in the Hippocampus. Representative samples of acetyl-H3 immunoreactivity in the hippocampus in the CMF and saline groups (upper panel). Scale bar = 40 μm. CMF administration significantly increased histone acetylation in the hippocampus, striatum, and prefrontal brain regions (lower panel, left). However, overall decreased in histone deacetylase activity was seen in the hippocampus of CMF-treated rats when compared to the saline group (lower panel, right). *p < 0.05.