Retigabine alleviates cognitive deficits, decreases neuropathology and activates the AKT/GSK-3β pathway in APP/PS1 transgenic mice

Neuronal hyperexcitability is crucial to the pathogenesis of Alzheimer's disease (AD). Activating the Kv7 channel is an effective way to reduce neuronal excitability. The Kv7 channel opener retigabine (RTG) has been demonstrated to alleviate spatial memory deficits in APP/PS1 transgenic mice. However, the mechanism by which RTG reduces cognitive deficits in APP/PS1 mice remains unclear. In this study, we revealed that RTG could ameliorate learning and spatial memory deficits in APP/PS1 mice during novel object recognition and Morris water maze tests. Meanwhile, RTG increased NeuN neuronal fluorescence intensity, increased the expression of the synaptic proteins postsynaptic density protein 95 (PSD95) and synaptophysin (SYN), improved synaptic plasticity, increased insulin-degrading enzyme (IDE) expression, decreased beta-secretase 1 (BACE1) expression, reduced Aβ 1–40 and Aβ 1–42 levels, and increased pAKT (ser473) and pGSK-3β (ser9) expression. These results indicated that RTG alleviates learning and spatial memory deficits in APP/PS1 mice, with potential mechanisms involving a reduction in neuronal loss, attenuation of synaptic damage, a decrease in β-amyloid (Aβ) deposition, and activation of the AKT/GSK-3β pathway.