AbstractIncreasing evidence suggests that Alzheimer's disease (AD) progression is driven by a vicious cycle of soluble β‐amyloid (Aβ)‐induced neuronal hyperactivity. Thus, breaking this vicious cycle by suppressing neuronal hyperactivity may represent a logical approach to stopping AD progression. In support of this, we have recently shown that genetically and pharmacologically limiting ryanodine receptor 2 (RyR2) open time prevented neuronal hyperactivity, memory impairment, dendritic spine loss, and neuronal cell death in a rapid, early onset AD mouse model (5xFAD). Here, we assessed the impact of limiting RyR2 open time on AD‐related deficits in a relatively late occurring, slow developing AD mouse model (3xTG‐AD) that bears more resemblance (compared to 5xFAD) to that of human AD. Using behavioral tests, long‐term potentiation recordings, and Golgi and Nissl staining, we found that the RyR2‐E4872Q mutation, which markedly shortens the open duration of the RyR2 channel, prevented learning and memory impairment, defective long‐term potentiation, dendritic spine loss, and neuronal cell death in the 3xTG‐AD mice. Furthermore, pharmacologically shortening the RyR2 open time with R‐carvedilol rescued these AD‐related deficits in 3xTG mice. Therefore, limiting RyR2 open time may offer a promising, neuronal hyperactivity‐targeted anti‐AD strategy.