Brains of endurance athletes differ in the association areas but not in the primary areas

Abstract

Regular participation in sports results in a series of physiological adaptations. However, little is known about the brain adaptations to physical activity. Here we aimed to investigate whether young endurance athletes and non‐athletes differ in the gray and white matter of the brain and whether cardiorespiratory fitness (CRF) is associated with these differences. We assessed the CRF, volumes of the gray and white matter of the brain using structural magnetic resonance imaging (sMRI), and brain white matter connections using diffusion magnetic resonance imaging (dMRI) in 20 young male endurance athletes and 21 healthy non‐athletes. While total brain volume was similar in both groups, the white matter volume was larger and the gray matter volume was smaller in the athletes compared to non‐athletes. The reduction of gray matter was located in the association areas of the brain that are specialized in processing of sensory stimuli. In the microstructure analysis, significant group differences were found only in the association tracts, for example, the inferior occipito‐frontal fascicle (IOFF) showing higher fractional anisotropy and lower radial diffusivity, indicating stronger myelination in this tract. Additionally, gray and white matter brain volumes, as well as association tracts correlated with CRF. No changes were observed in other brain areas or tracts. In summary, the brain signature of the endurance athlete is characterized by changes in the integration of sensory and motor information in the association areas.

A decade of progress in sports and exercise neuroscience from 2012 to 2022: A review and perspectives

“…行过程中最佳和最差表现相关的皮层活动，定制相关的神经反馈。Arns 等人 [109] 通过首次任务的 EEG 图谱，找出每名参与者达到最佳的前额叶大脑状态时的波形与振幅，基于此为他们制定了 个性化的神经反馈训练方式，并最终成功提升了业余高尔夫球员的高尔夫推杆表现。 竞技体育领域的 NFT 研究数量增长也催生了相应的综述性研究。总体而言，前人元分析的 结果表明，NFT 对改变 EEG 功率有小效应量，并对改善运动员的运动表现有小到中等的效应量 [110,111] 、对改善其反应时和决策亦有小的效应量 [110] 效率；而对于更复杂的、陈述性的控制任务来说，专家则应该表现出更高的神经熟练度 [113,114] 。 对于三个假说之间的关系，Filho 等人 [115] 对基于 EEG 的研究的元分析结果表明，它们在解释最 佳运动表现时，可能是协同作用、相互补充的，具体表现为：最佳运动表现既与整个皮层中的α 波和θ波有关，又尤其体现于前额叶的高α波和低θ波变化；对于同样的任务来说，专家的大脑 相比新手总是更放松。Li 和 Smith [116] 进一步对 EEG、fMRI 和 fNIRS 的 NEH 研究进行了综述。 他们认为，研究结果在总体上支持了 NEH 的有效性，但 NEH 的解释力会受到运动员特质、运 动特征和具体事件与情境的影响，需要具体情况具体分析。 神经扩展假说(neural expansion hypothesis, NExH)与神经效率假说的观点相反，认为专家 的神经活动比新手激活更多。基于专家的专业知识，诱发更多脑区的协同参与，最终提升运动表 现。Bilalić 等人 [117] 采用 fMRI 探究象棋的专家-新手差异，发现虽然两组的大脑外侧都有激活， 但是专家的激活更明显。同时，两组都激活了左侧的颞中后回，但是只有专家组激活了右侧的颞 中后回，表现出进一步的熟练物体识别。Kim 等人 [118] 成绩 [119] 。 比如， 耐力运动员大脑白质体积更大、 专门处理感觉刺激相关区域的灰质体积更小 [120] ， 体育运动经验会影响左背外侧前运动皮层、观看和参与体育运动会改变辅助理解的神经网络等 [119] 。 内部模型假说(internal models hypothesis, IMH)认为专家通过特定的脑活动模拟相关控制 系统的输入(比如视角、距离、重量等)和输出(比如动作、力度、手眼协调等)，来获得更好 的运动表现 [121] 。比如，Balser 等人 [91] 采用 fMRI 探究了网球和排球专家在预测发球方向时的脑区 活动，发现相比于新手，专家的动作-观察网络(特别是小脑)结构的激活更强，说明专家采用 了预测性内部模型来解决预期任务。 至关重要的作用 [130] 。因此，内感受不仅为个体提供了独特的主观体验，同时也被认为直接影响 着运动表现的效果，如，运动知觉、运动预期、运动决策和自我调节等心理过程。另一方面，内 感受也是一座联系身体、心理与大脑的桥梁，强调了身体在所有这些与运动有关的心理过程中的 作用。国内有研究者近期关注了运动表现与内感受的关系，构建了一个发生机制的理论框架，阐 述了运动情境下的身体，如何在外界环境发生改变的情况下，通过与大脑和心理的整合，持续保 持相对的内稳态的过程 [131] 。此外，该综述也回顾了运动专家的相关研究，提出了这些运动专家…”

Furin-Catalyzed Enhanced Magnetic Resonance Imaging Probe for Differential Diagnosis of Malignant Breast Cancers

“…To this end, a noninvasive and convenient method was explored to distinguish different BCs at the molecular level. Compared with X-ray, computed tomography (CT), and ultrasound (US), magnetic resonance imaging (MRI) has diagnostic advantages, such as a noninvasive nature, high-resolution images of soft tissues, absence of radiation, and multiparameters, hence it is widely used in tumor and other disease imaging in clinics. − For enhanced imaging of lesions, contrast agent-enhanced MRI is needed in clinics. − Up to now, enhanced MRI examinations mostly focus on structural MRI (sMRI). − Structural imaging can clearly show the physical structural characteristics of the lesion, such as its location, size, and shape, to a certain extent. However, tumor-specific molecular information in the lesion tissue could not be detected.…”