HDAC 4, 5, and 9 revealed marked decreases in their mRNA levels throughout the granule and pyramidal cell layers at the late interval, 28 days after pilocarpine‐induced status epilepticus (HDAC4, DG: 60.2 ± 2.96% of control, p < 0.01; CA3: 74.6 ± 5.11%, p < 0.05; CA1: 64.0 ± 7.12%, p < 0.05 (Figs 4c and 5c); HDAC5, DG: 59.5 ± 9.85% of control, p < 0.05; CA3: 67.3 ± 12.59%, p > 0.05; CA1: 64.1 ± 17.34%, p < 0.05 (Figs 4f and 5f); HDAC9, DG: 25.8 ± 9.10% of control, p < 0.001; CA3: 30.3 ± 7.02%, p < 0.001; CA1: 38.0 ± 19.41%, p < 0.001 (Figs 4i and 5l). Here, HDAC5 is linked to status epilepticus.