Deficits in cognition and memory are associated with many disease states including Alzheimer’s disease, Rubinstein Taybi Syndrome and Schizophrenia. Altered acetylation states and the effects on specific gene expression and protein regulation underlie components of central nervous system (CNS) disorders. Hypoacetylation states are found in neurological contexts and histone deacetylases (HDACs) offer an attractive target to remedy these altered acetylation states. We describe our efforts to understand the biology of individual HDAC isoforms, optimize small molecule HDAC inhibitors with greater isoform selectivity, improve CNS drug properties and demonstrate efficacy in mouse models of learning and memory