Crebinostat is a potent histone deacetylase (HDAC) inhibitor, inhibiting HDAC1, HDAC2, HDAC3, and HDAC6 with IC50s of 0.7 nM, 1.0 nM, 2.0 nM, and 9.3 nM, respectively.Crebinostat increases the density of synapsin-1 punctae along dendrites in neurons in vitro. Crebinostat increased the density of synapsin-1 punctae along dendrites in neurons in vitro. crebinostat modulated chromatin-mediated neuroplasticity and enhanced memory in mice. crebinostat induced histone H3 and histone H4 acetylation and enhanced the expression of the cAMP-responsive element binding protein (CREB) target gene, Egr1. Crebinostat induces histone H3 and histone H4 acetylation and enhances the expression of Egr1, a cAMP response element binding protein (CREB) target.