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.

最近的工作将大脑概念化为由子网络或模块组组成的网络。大脑网络的“灵活性”反映了组成模块的动态重新配置。本研究利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），研究了有氧运动干预对模块化群落结构动态重排（神经灵活性的衡量标准）的影响。内侧颞叶（MTL）网络。 MTL 是最早受阿尔茨海默病影响的大脑区域之一。它也是神经可塑性的主要部位，对运动的影响敏感。在对 34 名健康老年人进行的两组非随机、重复测量和匹配对照设计中，我们观察到 MTL 网络内与运动相关的灵活性增加。此外，MTL 网络灵活性介导了有氧运动对记忆灵活性的有益影响，这是通过将过去的学习概括为新任务需求的能力来衡量的。我们的研究结果表明，运动对 MTL 功能具有恢复和保护作用，从而导致以复杂的沟通模式相互作用的区域网络的动态发展。这些重新配置可能是运动引起的泛化认知测量改善的基础，而泛化认知测量对 MTL 的细微变化很敏感。