Laboratory of Exercise Biochemistry and Neuroendocrinology, Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-8574, Ibaraki, Japan.
Department of Sport Neuroscience, Advanced Research Initiative for Human High Performance (ARIHHP), Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba 305-8574, Ibaraki, Japan.
Sci Rep. 2018 Jan 19;8(1):1285. doi: 10.1038/s41598-018-19445-4.
Glycogen loading (GL), a well-known type of sports conditioning, in combination with exercise and a high carbohydrate diet (HCD) for 1 week enhances individual endurance capacity through muscle glycogen supercompensation. This exercise-diet combination is necessary for successful GL. Glycogen in the brain contributes to hippocampus-related memory functions and endurance capacity. Although the effect of HCD on the brain remains unknown, brain supercompensation occurs following exhaustive exercise (EE), a component of GL. We thus employed a rat model of GL and examined whether GL increases glycogen levels in the brain as well as in muscle, and found that GL increased glycogen levels in the hippocampus and hypothalamus, as well as in muscle. We further explored the essential components of GL (exercise and/or diet conditions) to establish a minimal model of GL focusing on the brain. Exercise, rather than a HCD, was found to be crucial for GL-induced hyper-glycogen in muscle, the hippocampus and the hypothalamus. Moreover, EE was essential for hyper-glycogen only in the hippocampus even without HCD. Here we propose the EE component of GL without HCD as a condition that enhances brain glycogen stores especially in the hippocampus, implicating a physiological strategy to enhance hippocampal functions.
糖原负荷（GL）是一种众所周知的运动调节方式，通过 1 周的运动和高碳水化合物饮食（HCD）相结合，可以增强个体的耐力能力，通过肌肉糖原超补偿实现。这种运动-饮食的结合对于成功的 GL 是必要的。大脑中的糖原有助于海马体相关的记忆功能和耐力能力。虽然 HCD 对大脑的影响尚不清楚，但 GL 的一个组成部分——剧烈运动（EE）后会发生大脑超补偿。因此，我们采用了 GL 的大鼠模型，并检查了 GL 是否会增加大脑和肌肉中的糖原水平，结果发现 GL 增加了海马体和下丘脑以及肌肉中的糖原水平。我们进一步探讨了 GL 的基本组成部分（运动和/或饮食条件），以建立一个专注于大脑的 GL 最小模型。我们发现，运动而不是 HCD 对于 GL 诱导的肌肉、海马体和下丘脑的高糖原至关重要。此外，即使没有 HCD，EE 对于仅在海马体中的高糖原也是必不可少的。在这里，我们提出了不包含 HCD 的 GL 的 EE 成分作为一种增强大脑糖原储存的条件，特别是在海马体中，暗示了一种增强海马体功能的生理策略。
