Exercise regulates brain-derived neurotrophic factor (BDNF) using epigenetic mechanisms. (A) Voluntary exercise increased histone H3 acetylation in hippocampi of rats assessed using chromatin immunoprecipitation (ChIP) assay. Primers specific to BDNF promoter IV were used to amplify the DNA from the AceH3 immunoprecipitates, and the relative enrichments of the BDNF promoter IV in the AceH3 immunoprecipitates were measured using real-time PCR. Equal amounts of DNA from sedentary (Sed) or exercised (Exc) rat hippocampi were used for immunoprecipitation. Data are presented as means ± SEM; *, P < 0.05. (B) Levels of AceH3 and H3 were assessed by Western blot analysis in the same hippocampal tissue used for the ChIP assay, and found a significant (**, P < 0.01) increase in the ratio AceH3/H3 in the exercise group compared to sedentary rats. Reprinted, with permission, from reference (75), p. 387.