人类和动物研究表明，运动有助于促进健康的大脑发育和功能，包括促进海马区的生长。接受颅脑放疗的儿童癌症幸存者表现出海马体积缺失，并且面临认知功能受损的风险，因此他们可能会从定期运动中获益。尽管通过磁共振成像（MRI）对运动引起的形态学变化在人类和动物模型中进行了表征，但在发育过程中和颅脑放疗后评估整个大脑的变化仍然缺乏。在本研究中，我们使用高分辨率纵向MRI评估了运动对儿童颅脑放疗小鼠模型的影响。雌性小鼠在幼儿等龄阶段（P16）接受了全脑放疗（7 Gy）或假放疗（0 Gy）。辐照后一周，小鼠被放置在常规笼子或配备跑轮的笼子中。进行体内MRI检查，评估辐照和运动的影响。我们使用线性混合效应模型评估了体积和皮质厚度的变化。运动显著增加了某些大脑区域的体积，尤其是海马体，这在辐照和未辐照的小鼠中都有体现。体积增加超过了颅脑放疗引起的缺陷。我们还对亚区域海马体积的运动和辐射效应进行了表征。此外，我们描绘了皮质厚度的发育变化，并发现其峰值在P23至P43之间不等，具体取决于区域。运动在3周的自愿运动后还引起了皮质厚度的区域性变化，而辐照并没有实质性改变皮质厚度。我们的结果显示，运动有可能改变辐照和未辐照小鼠的神经解剖结局。这支持当前正在进行的研究，探索运动作为提高儿童神经认知发展策略，尤其是那些接受颅脑放疗的儿童领域的应用。《NMR in Biomedicine》© 2023 作者。由John Wiley & Sons Ltd发表的《NMR in Biomedicine》杂志。

Human and animal studies suggest that exercise promotes healthy brain development and function, including promoting hippocampal growth. Childhood cancer survivors that have received cranial radiotherapy exhibit hippocampal volume deficits and are at risk of impaired cognitive function, thus they may benefit from regular exercise. While morphological changes induced by exercise have been characterized using magnetic resonance imaging (MRI) in humans and animal models, evaluation of changes across the brain through development and following cranial radiation is lacking. In this study, we used high-resolution longitudinal MRI through development to evaluate the effects of exercise in a pediatric mouse model of cranial radiation. Female mice received whole-brain radiation (7 Gy) or sham radiation (0 Gy) at an infant equivalent age (P16). One week after irradiation, mice were housed in either a regular cage or a cage equipped with a running wheel. In vivo MRI was performed prior to irradiation, and at three subsequent timepoints to evaluate the effects of radiation and exercise. We used a linear mixed-effects model to assess volumetric and cortical thickness changes. Exercise caused substantial increases in the volumes of certain brain regions, notably the hippocampus in both irradiated and nonirradiated mice. Volume increases exceeded the deficits induced by cranial irradiation. The effect of exercise and irradiation on subregional hippocampal volumes was also characterized. In addition, we characterized cortical thickness changes across development and found that it peaked between P23 and P43, depending on the region. Exercise also induced regional alterations in cortical thickness after 3 weeks of voluntary exercise, while irradiation did not substantially alter cortical thickness. Our results show that exercise has the potential to alter neuroanatomical outcomes in both irradiated and nonirradiated mice. This supports ongoing research exploring exercise as a strategy for improving neurocognitive development for children, particularly those treated with cranial radiotherapy.NMR in Biomedicine© 2023 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.