Biological and Biomedical Sciences Program, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514.
Department of Mathematics, Dartmouth College, Hanover, NH 03755.
Proc Natl Acad Sci U S A. 2022 Nov;119(44):e2203682119. doi: 10.1073/pnas.2203682119. Epub 2022 Oct 25.
Aging is associated with gradual changes in cognition, yet some individuals exhibit protection against age-related cognitive decline. The topological characteristics of brain networks that promote protection against cognitive decline in aging are unknown. Here, we investigated whether the robustness and resilience of brain networks, queried via the delineation of the brain's core network structure, relate to age and cognitive performance in a cross-sectional dataset of healthy middle- and old-aged adults ( = 478, ages 40 to 90 y). First, we decomposed each subject's functional brain network using -shell decomposition and found that age was negatively associated with robust core network structures. Next, we perturbed these networks, via attack simulations, and found that resilience of core brain network nodes also declined in relationship to age. We then partitioned our dataset into middle- (ages 40 to 65 y, = 300) and old- (ages 65 to 90 y, = 178) aged subjects and observed that older individuals had less robust core connectivity and resilience. Following these analyses, we found that episodic memory was positively related to robust connectivity and core resilience, particularly within the default node, limbic, and frontoparietal control networks. Importantly, we found that age-related differences in episodic memory were positively related to core resilience, which indicates a potential role for core resilience in protection against cognitive decline. Together, these findings suggest that robust core connectivity and resilience of brain networks could facilitate high cognitive performance in aging.
衰老是与认知逐渐变化相关的，但有些个体表现出对与年龄相关的认知衰退的保护。促进衰老过程中认知衰退保护的大脑网络拓扑特征尚不清楚。在这里，我们通过描绘大脑核心网络结构来研究大脑网络的稳健性和弹性是否与健康中老年成年人（n = 478，年龄 40 至 90 岁）的横断面数据集的年龄和认知表现相关。首先，我们使用 -shell 分解分解了每个受试者的功能大脑网络，发现年龄与稳健的核心网络结构呈负相关。接下来，我们通过攻击模拟对这些网络进行了扰动，并发现核心脑网络节点的弹性也与年龄相关下降。然后，我们将数据集分为中年（年龄 40 至 65 岁，n = 300）和老年（年龄 65 至 90 岁，n = 178）年龄组，并观察到老年个体的核心连接和弹性较小。在进行这些分析之后，我们发现情景记忆与稳健的连接和核心弹性呈正相关，特别是在默认节点、边缘和额顶叶控制网络中。重要的是，我们发现情景记忆与核心弹性的年龄相关差异呈正相关，这表明核心弹性在保护认知衰退方面可能发挥作用。总的来说，这些发现表明大脑网络的稳健核心连接和弹性可以促进衰老过程中的高认知表现。
