Wu Linyan, Zhang Wenlong, Li Sinan, Li Youjun, Yuan Ye, Huang Liang, Cao Tiantian, Fan Liming, Chen Jiawen, Wang Jingyun, Liu Tian, Wang Jue
IEEE Trans Neural Syst Rehabil Eng. 2023;31:2060-2068. doi: 10.1109/TNSRE.2023.3265378. Epub 2023 Apr 26.
Transcranial alternating current stimulation (tACS) is considered to have a positive effect on the rehabilitation of Alzheimer's disease (AD) as an intervention method that matches stimulation frequency to neurogenesis frequency. However, when tACS intervention is delivered to a single target, the current received by brain regions outside the target may be insufficient to trigger neural activity, compromising the effectiveness of stimulation. Therefore, it is worth studying how single-target tACS restores gamma-band activity in the whole hippocampal-prefrontal circuit during rehabilitation. We used Sim4Life software to conduct finite element methods (FEM) on the stimulation parameters to ensure that tACS intervened only in the right hippocampus (rHPC) and did not activate the left hippocampus (lHPC) or prefrontal cortex (PFC). We stimulated the rHPC by tACS for 21 days to improve the memory function of AD mice. We simultaneously recorded local field potentials (LFPs) in the rHP, lHPC and PFC and evaluated the neural rehabilitative effect of tACS stimulation with power spectral density (PSD), cross-frequency coupling (CFC) and Granger causality. Compared to the untreated group, the tACS group exhibited an increase in the Granger causality connection and CFC between the rHPC and PFC, a decrease in those between the lHPC and PFC, and enhanced performance on the Y-maze test. These results suggest that tACS may serve as a noninvasive method for Alzheimer's disease rehabilitation by ameliorating abnormal gamma oscillation in the hippocampal-prefrontal circuit.
经颅交流电刺激（tACS）作为一种刺激频率与神经发生频率相匹配的干预方法，被认为对阿尔茨海默病（AD）的康复具有积极作用。然而，当tACS干预作用于单个靶点时，靶点外脑区接收到的电流可能不足以触发神经活动，从而影响刺激效果。因此，研究单靶点tACS在康复过程中如何恢复整个海马-前额叶回路的γ波段活动具有重要意义。我们使用Sim4Life软件对刺激参数进行有限元方法（FEM）分析，以确保tACS仅干预右侧海马体（rHPC），而不激活左侧海马体（lHPC）或前额叶皮质（PFC）。我们通过tACS刺激rHPC 21天，以改善AD小鼠的记忆功能。我们同时记录rHP、lHPC和PFC中的局部场电位（LFP），并通过功率谱密度（PSD）、交叉频率耦合（CFC）和格兰杰因果关系评估tACS刺激的神经康复效果。与未治疗组相比，tACS组rHPC与PFC之间的格兰杰因果关系连接和CFC增加，lHPC与PFC之间的则减少，并且在Y迷宫测试中的表现得到改善。这些结果表明，tACS可能通过改善海马-前额叶回路中的异常γ振荡，作为一种用于阿尔茨海默病康复的非侵入性方法。
