GABA decreases H3K27 mono methylation on the Gabrb1 promoter. Real time PCR analysis of ChIP assays show a statistically significant (***) decrease (n=5) of H3K27 monomethylation at the core promoter region (P = 0.0001) (A) with no significant change in the status of trimethylation (n=5, p=0.1184). Y-axis represents relative signal of H3K27 (mono- or tri-) methylation as compared to vehicle control (set as 1). A Student’s t-test was used to investigate the statistical significance of mono- and trimethylation. (B) Radiographic display showing amplified promoter fragments immunoprecipitated with H3K27me1 (mono) and H3K27me3 (tri) antibodies. Total input DNA and IgG lanes are marked by “TOT” and “-“, respectively. Results are expressed as mean values ± SEM.