Graduate Collaborative Training Base of Academy of Military Medical Sciences, Hengyang Medical School, University of South China, Hengyang, Hunan, 421001, China.
Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing,1 00850, China.
Curr Alzheimer Res. 2023;20(5):350-359. doi: 10.2174/1567205020666230808122643.
Alzheimer's disease (AD) is a well-known neurodegenerative disease that gradually induces neural network dysfunction and progressive memory deficits. Neural network activity is represented by rhythmic oscillations that influence local field potentials (LFPs). However, changes in hippocampal neural rhythmic oscillations in the early stage of AD remain largely unexplored.
This study investigated neural rhythmic oscillations in 3-month-old APP/PS1 and 5x- FAD mice to assess early neural connectivity in AD.
LFPs were recorded from the hippocampal CA1 region with implanted microelectrode arrays while the mice were in the awake resting stage. Welch fast Fourier transforms, continuous wavelet transforms, and phase-amplitude coupling analyses were used to compute the power density of different frequency bands and phase-amplitude modulation indices in the LFPs.
Our results showed impaired theta, low gamma, and high gamma frequency band power in APP/PS1 and 5xFAD mice during the awake resting stage. AD mice also showed decreased delta, alpha, and beta frequency band power. Impaired theta-low gamma and theta-high gamma phaseamplitude coupling were observed in 5xFAD mice.
This study revealed neural network activity differences in oscillation power and cross-frequency coupling in the early stage of AD, providing a new perspective for developing biomarkers for early AD diagnosis.
阿尔茨海默病（AD）是一种众所周知的神经退行性疾病，它会逐渐导致神经网络功能障碍和进行性记忆缺失。神经网络活动由影响局部场电位（LFPs）的节律性振荡来表示。然而，AD 早期海马体神经节律性振荡的变化在很大程度上仍未得到探索。
本研究通过记录植入微电极阵列的 APP/PS1 和 5x-FAD 小鼠在清醒静息状态下的海马 CA1 区 LFPs，检测 AD 早期的神经连接变化。
使用 Welch 快速傅里叶变换、连续小波变换和相位-振幅耦合分析，计算 LFPs 中不同频段的功率密度和相位-振幅调制指数。
研究结果显示，在清醒静息状态下，APP/PS1 和 5xFAD 小鼠的 theta、低 gamma 和高 gamma 频段功率受损。AD 小鼠的 delta、alpha 和 beta 频段功率也降低。在 5xFAD 小鼠中还观察到 theta-低 gamma 和 theta-高 gamma 相位-振幅耦合受损。
本研究揭示了 AD 早期神经网络活动在振荡功率和跨频耦合方面的差异，为早期 AD 诊断的生物标志物开发提供了新视角。
