Previous experience on MWM induces a marked, albeit transient, improvement in acquisition. Naive 3xTg-AD mice (A) are markedly impaired during acquisition relative to NonTg mice, whereas experienced 3xTg-AD mice (B) exhibit a clear benefit of previous training that emerges at 9 months of age and gradually disappears by 15–18 months of age. Each cluster of results represents the daily means across each group. Error bars indicate SE.