Enhancement of memory consolidation by the histone deacetylase inhibitor sodium butyrate in aged rats

•Sodium butyrate produced memory enhancement and persistence in aged rats.•Memory formation in younger rats was not affected by sodium butyrate.•Aged rats with normal memory might be particularly sensitive to sodium butyrate.

Here we show that a systemic injection of the histone deacetylase inhibitor (HDACi) sodium butyrate (NaB) immediately after training in a step-down inhibitory avoidance task produced an enhancement of memory consolidation that persisted across consecutive retention tests during 14 days in aged rats, while it did not significantly affect memory in young adults. Control aged and young adult rats showed comparable basal levels of memory retention. Our results suggest that HDACis can display memory-enhancing effects specific for aged animals, even in the absence of age-related memory impairment.