As Alzheimer's disease (AD) pathology accumulates, resting-state functional connectivity (rs-fc) within and between brain networks decreases, and fluctuations in cognitive performance known as intraindividual variability (IIV) increase. Here, we assessed the relationship between IIV and anticorrelations in rs-fc between the default mode network (DMN)-dorsal attention network (DAN) in cognitively normal older adults and symptomatic AD participants. We also evaluated the relationship between cerebrospinal fluid (CSF) biomarkers of AD (amyloid-beta [Aβ42] and tau) and IIV-anticorrelation in rs-fc. We observed that cognitive IIV and anticorrelations between DMN × DAN were higher in individuals with AD compared with cognitively normal participants. As DMN × DAN relationship became more positive, cognitive IIV increased, indicating that stronger anticorrelations between networks support more consistent cognitive performance. Moderation analyses indicated that continuous CSF Aβ42, but not CSF total tau, moderated the relationship between cognitive IIV and DMN × DAN, collectively demonstrating that greater amyloid burden and alterations in functional network dynamics are associated with cognitive changes seen in AD. These findings are valuable, as they suggest that amyloid affects cognitive functioning during the early stages of AD.

中文翻译：

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CSF Aβ42 调节脑功能网络动力学与个体内部认知变异性之间的关系

随着阿尔茨海默病 (AD) 病理学的积累，大脑网络内部和之间的静息状态功能连接 (rs-fc) 减少，并且被称为个体内变异 (IIV) 的认知表现波动增加。在这里，我们评估了认知正常的老年人和有症状的 AD 参与者的 IIV 与 rs-fc 中默认模式网络（DMN）-背侧注意力网络（DAN）之间的反相关性之间的关系。我们还评估了 AD 的脑脊液 (CSF) 生物标志物（淀粉样蛋白-β [Aβ42] 和 tau）与 rs-fc 中的 IIV 抗相关性之间的关系。我们观察到，与认知正常的参与者相比，AD 患者的认知 IIV 和 DMN × DAN 之间的反相关性更高。随着 DMN × DAN 关系变得更加积极，认知 IIV 增加，表明网络之间更强的反相关性支持更一致的认知表现。调节分析表明，连续的 CSF Aβ42，而不是 CSF 总 tau，调节了认知 IIV 和 DMN × DAN 之间的关系，共同表明更大的淀粉样蛋白负担和功能网络动力学的改变与 AD 中看到的认知变化有关。这些发现很有价值，因为它们表明淀粉样蛋白在 AD 的早期阶段会影响认知功能。共同证明，更大的淀粉样蛋白负担和功能网络动力学的改变与 AD 中看到的认知变化有关。这些发现很有价值，因为它们表明淀粉样蛋白在 AD 的早期阶段会影响认知功能。共同证明，更大的淀粉样蛋白负担和功能网络动力学的改变与 AD 中看到的认知变化有关。这些发现很有价值，因为它们表明淀粉样蛋白在 AD 的早期阶段会影响认知功能。