HDAC9 and epilepsy: The class I HDAC inhibitor CI-994 and the HDAC1-specific inhibitor parthenolide may enhance synaptic plasticity in hippocampal neurons by inhibiting astrocyte and microglia immunoreactivity, thereby ameliorating epilepsy-induced cognitive impairment (Jia et al., 2023; Dai et al., 2021; Burns et al., 2022).