Aβ沉积形成的老年斑和tau蛋白过度磷酸化造成的神经纤维缠结是阿尔茨海默病的重要病理特征。最新研究表明，Aβ与tau蛋白具有神经毒性交互作用，通过促进 Fyn/NMDAR/PSD95复合物的形成，引起神经细胞毒性和突触损伤。我们前期研究表明还脑益聪方能够显著减轻Aβ的沉积和tau蛋白磷酸化水平，在此基础上提出“还脑益聪方通过干预Fyn/NMDAR/PSD95复合物的稳定性，调控Aβ与tau蛋白的神经毒性交互作用，从而改善神经细胞的突触可塑性”的假说。为验证这一假说，本研究以APP/PS1/tau大鼠及其原代神经元细胞为干预对象，采用水迷宫、电生理、免疫荧光、Western blot、免疫共沉淀等技术，观察大鼠学习记忆、海马突触可塑性、磷酸化tau蛋白以及Fyn/NMDAR/PSD95复合物，旨在阐释还脑益聪方干预“Aβ-tau蛋白的神经毒性交互作用”的机制。

The senile plague formed by Aβ (amyloid β-protein，Aβ) deposition and neurofibrillary tangles due to hyperphosphorylation of tau are two key pathological features of Alzheimer's disease. Recent studies indicate that the interaction between Aβ and tau promote the neurotoxicity, by facilitating the formation of the Fyn/NMDAR/PSD95 complex, thus attributing to the neural toxicity and synaptic impairments. Our previous research has shown that Huannao yicong decoction (HNYCD) could reduce the Aβ deposition and tau phosphorylation. Hence, we put forward the hypothesis that HNYCD regulates the synaptic plasticity by destabilizing the Fyn/NMDAR/PSD95 complex, so as to retarding the neurotoxic interaction of Aβ and tau. To specify the underlie mechanisms, Morris water maze experiment, electrophysiological methods, Western blot, co-immunoprecipitation will be used, to evaluate the learning and memory ability, hippocampal synaptic plasticity, Aβ burdens, phosphorylation of tau and content of Fyn/NMDAR/PSD95 in APP/PS1/tau rats and its neuronal cells, aiming at illustrating the mechanism of Huannao Yicong decoction in alleviating the neurotoxic interaction of Aβ and tau in Alzheimer's disease.