Here we tested the effect of JQ1—a small-molecule inhibitor of the chromatin readers BRD2, BRD3, BRD4 and BRDT—on brain function and show that JQ1 is able to enhance cognitive performance and long-term potentiation in wild-type animals and in a mouse model for Alzheimer’s disease. Here, BRD3 is linked to early-onset autosomal dominant Alzheimer disease.