Park Yeseung, Yoon Euisuk, Park Jieun, Kim Jun Sung, Han Ji Won, Bae Jong Bin, Kim Sang-Su, Kim Do-Won, Woo Se Joon, Park Jaehyeok, Lee Wheesung, Yoo Seunghyup, Kim Ki Woong
Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, Korea.
Department of Brain and Cognitive Science, College of Natural Sciences, Seoul National University, Seoul, Korea.
Geroscience. 2025 Feb;47(1):1019-1037. doi: 10.1007/s11357-024-01281-2. Epub 2024 Jul 15.
Gamma entrainment through sensory stimulation has the potential to reduce the pathology of Alzheimer's disease in mouse models. However, clinical trials in Alzheimer's disease (AD) patients have yielded inconsistent results, necessitating further investigation. This single-center pre-post intervention study aims to explore the influence of white matter microstructural integrity on gamma rhythm propagation from the visual cortex to AD-affected regions in 31 cognitively normal volunteers aged ≥ 65. Gamma rhythm propagation induced by optimal FLS was measured. Diffusion tensor imaging was employed to assess the integrity of white matter tracts of interest. After excluding 5 participants with a deficit in steady-state visually evoked potentials, 26 participants were included in the final analysis. In the linear regression analyses, gamma entrainment was identified as a significant predictor of gamma propagation (p < 0.001). Furthermore, the study identified white matter microstructural integrity as a significant predictor of gamma propagation by flickering light stimulation (p < 0.05), which was specific to tracts that connect occipital and temporal or frontal regions. These findings indicate that, despite robust entrainment of gamma rhythms in the visual cortex, their propagation to other regions may be impaired if the microstructural integrity of the white matter tracts connecting the visual cortex to other areas is compromised. Consequently, our findings have expanded our understanding of the prerequisites for effective gamma entrainment and suggest that future clinical trials utilizing visual stimulation for gamma entrainment should consider white matter tract microstructural integrity for candidate selection and outcome analysis.
通过感觉刺激实现的伽马波同步化有潜力减轻小鼠模型中阿尔茨海默病的病理特征。然而，针对阿尔茨海默病（AD）患者的临床试验结果并不一致，因此有必要进一步研究。这项单中心干预前后研究旨在探讨白质微观结构完整性对31名年龄≥65岁的认知正常志愿者从视觉皮层到受AD影响区域的伽马节律传播的影响。测量了最佳闪光刺激（FLS）诱导的伽马节律传播。采用扩散张量成像来评估感兴趣的白质束的完整性。在排除5名稳态视觉诱发电位有缺陷的参与者后，最终分析纳入了26名参与者。在线性回归分析中，伽马波同步化被确定为伽马传播的显著预测因子（p<0.001）。此外，该研究确定白质微观结构完整性是闪烁光刺激引起的伽马传播的显著预测因子（p<0.05），这对白质束连接枕叶和颞叶或额叶区域具有特异性。这些发现表明，尽管视觉皮层中伽马节律有强大的同步化，但如果连接视觉皮层与其他区域的白质束的微观结构完整性受到损害，它们向其他区域的传播可能会受损。因此，我们的发现扩展了我们对有效伽马波同步化先决条件的理解，并表明未来利用视觉刺激进行伽马波同步化的临床试验应考虑白质束微观结构完整性，以进行候选者选择和结果分析。
