HDAC6 and Cognitive impairment: Based on the demonstration that phosphorylation of tau on KXGS motifs is required for synaptic toxicity of Aβ (23,24), therapeutic intervention with an HDAC6 inhibitor to prevent deacetylation and subsequent phosphorylation of tau's KXGS motifs should halt the pathogenic cascade initiated by Aβ prior to the development of synaptic and cognitive deficits.