library_construction_protocol: The brainstem and trigeminal nerve roots on both sides were dissected trigeminal ganglion tissues were incubated with 1 mL IP buffer (20 mM HEPES [pH 7.9], 350 mM NaCl, 0.1% NP-40, 1 mM DTT, 0.2 mM PMSF, 2 mg/ml leupeptin and 2 mg/ml aprotinin) on ice for 30 min, then harvested nucleus by highest speed centrifugation. The supernatant containing nucleus were sonicated to break up the genomic DNA into 200–500 bp fragments. Next, 10% lysates were saved as input and the remaining were incubated with 1 μg IP-grade antibodies of H3K9ac (CST, #9649) and HDAC3 (Abclonal, A19537) at 4 °C overnight. This was followed by incubation for 2 h with Protein A beads at 37 °C to pull down the bound DNA fragments. 3′-dA overhangs were added to the H3K9ac or HDAC3 enriched or input DNA and ligated them to the adapter to build a DNA library.