Xue Xin, Wu Jia-Jia, Huo Bei-Bei, Xing Xiang-Xin, Ma Jie, Li Yu-Lin, Wei Dong, Duan Yu-Jie, Shan Chun-Lei, Zheng Mou-Xiong, Hua Xu-Yun, Xu Jian-Guang
School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Department of Rehabilitation Medicine, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Front Aging Neurosci. 2022 May 13;14:895934. doi: 10.3389/fnagi.2022.895934. eCollection 2022.
Normal aging causes profound changes of structural degeneration and glucose hypometabolism in the human brain, even in the absence of disease. In recent years, with the extensive exploration of the topological characteristics of the human brain, related studies in rats have begun to investigate. However, age-related alterations of topological properties in individual brain metabolic network of rats remain unknown. In this study, a total of 48 healthy female Sprague-Dawley (SD) rats were used, including 24 young rats and 24 aged rats. We used Jensen-Shannon Divergence Similarity Estimation (JSSE) method for constructing individual metabolic networks to explore age-related topological properties and rich-club organization changes. Compared with the young rats, the aged rats showed significantly decreased clustering coefficient () and local efficiency ( ) across the whole-brain metabolic network. In terms of changes in local network measures, degree () and nodal efficiency ( ) of left posterior dorsal hippocampus, and of left olfactory tubercle were higher in the aged rats than in the young rats. About the rich-club analysis, the existence of rich-club organization in individual brain metabolic networks of rats was demonstrated. In addition, our findings further confirmed that rich-club connections were susceptible to aging. Relative to the young rats, the overall strength of rich-club connections was significantly reduced in the aged rats, while the overall strength of feeder and local connections was significantly increased. These findings demonstrated the age-related reorganization principle of the brain structure and improved our understanding of brain alternations during aging.
正常衰老会导致人类大脑发生深刻的结构退化和葡萄糖代谢减退，即使在没有疾病的情况下也是如此。近年来，随着对人类大脑拓扑特征的广泛探索，针对大鼠的相关研究也已展开。然而，大鼠个体脑代谢网络中拓扑特性的年龄相关变化仍不清楚。在本研究中，共使用了48只健康的雌性斯普拉格-道利（SD）大鼠，其中包括24只年轻大鼠和24只老年大鼠。我们使用詹森-香农散度相似性估计（JSSE）方法构建个体代谢网络，以探索年龄相关的拓扑特性和富俱乐部组织变化。与年轻大鼠相比，老年大鼠全脑代谢网络的聚类系数（ ）和局部效率（ ）显著降低。就局部网络指标的变化而言，老年大鼠左后背部海马体的度（ ）和节点效率（ ）以及左嗅结节的 高于年轻大鼠。关于富俱乐部分析，证实了大鼠个体脑代谢网络中存在富俱乐部组织。此外，我们的研究结果进一步证实富俱乐部连接易受衰老影响。相对于年轻大鼠，老年大鼠富俱乐部连接的整体强度显著降低，而馈线和局部连接的整体强度显著增加。这些发现证明了脑结构的年龄相关重组原则，并增进了我们对衰老过程中大脑变化的理解。
