Although research has so far been confined to mouse studies, researchers are optimistic about the promise of histone deacetylase inhibitors in reversing age-related memory loss — both normal decline, and the far more dramatic loss produced by Alzheimer’s. The latest study reveals that memory impairment in the aging mouse is associated with altered hippocampal chromatin plasticity, specifically with the failure of histone H4 lysine 12 acetylation, leading to a failure to initiate the gene expression program associated with memory consolidation. Restoring this acetylation leads to the recovery of cognitive abilities.