Center for Molecular and Behavioral Neuroscience, Rutgers University-Newark, NJ, USA.
Center for the Neurobiology of Learning and Memory, Department of Neurobiology and Behavior, University of California, Irvine, CA, USA.
Neurobiol Learn Mem. 2021 Jan;177:107340. doi: 10.1016/j.nlm.2020.107340. Epub 2020 Nov 10.
Recent work has conceptualized the brain as a network comprised of groups of sub-networks or modules. "Flexibility" of brain network(s) indexes the dynamic reconfiguration of comprising modules. Using novel techniques from dynamic network neuroscience applied to high-resolution resting-state functional magnetic resonance imaging (fMRI), the present study investigated the effects of an aerobic exercise intervention on the dynamic rearrangement of modular community structure-a measure of neural flexibility-within the medial temporal lobe (MTL) network. The MTL is one of the earliest brain regions impacted by Alzheimer's disease. It is also a major site of neuroplasticity that is sensitive to the effects of exercise. In a two-group non-randomized, repeated measures and matched control design with 34 healthy older adults, we observed an exercise-related increase in flexibility within the MTL network. Furthermore, MTL network flexibility mediated the beneficial effect aerobic exercise had on mnemonic flexibility, as measured by the ability to generalize past learning to novel task demands. Our results suggest that exercise exerts a rehabilitative and protective effect on MTL function, resulting in dynamically evolving networks of regions that interact in complex communication patterns. These reconfigurations may underlie exercise-induced improvements on cognitive measures of generalization, which are sensitive to subtle changes in the MTL.
最近的研究将大脑概念化为由多个子网或模块组成的网络。“大脑网络的灵活性”指标是组成模块的动态重新配置。本研究使用动态网络神经科学的新技术，应用于高分辨率静息态功能磁共振成像（fMRI），调查了有氧运动干预对内侧颞叶（MTL）网络中模块化社区结构（衡量神经灵活性的指标）的动态重新排列的影响。MTL 是受阿尔茨海默病影响最早的大脑区域之一。它也是对运动敏感的神经可塑性的主要部位。在一项有 34 名健康老年人参与的两组成非随机、重复测量和匹配对照组设计中，我们观察到 MTL 网络中的灵活性与运动相关的增加。此外，MTL 网络的灵活性介导了有氧运动对记忆灵活性的有益影响，记忆灵活性通过将过去的学习推广到新的任务需求的能力来衡量。我们的结果表明，运动对 MTL 功能具有康复和保护作用，导致区域的动态演变网络以复杂的通信模式相互作用。这些重新配置可能是运动引起的概括认知测量改善的基础，这些改善对 MTL 的细微变化敏感。
