Thomas Riya, Zimmerman Scott D, Yuede Kayla M, Cirrito John R, Tai Leon M, Timson Benjamin F, Yuede Carla M
Department of Biomedical Sciences, Missouri State University, Springfield, MO 65897, USA.
Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Brain Sci. 2020 Feb 8;10(2):88. doi: 10.3390/brainsci10020088.
Three months of exercise training (ET) decreases soluble Aβ and Aβ levels in an intensity dependent manner early in life in Tg2576 mice (Moore et al., 2016). Here, we examined the effects of 12 months of low- and high- intensity exercise training on cognitive function and amyloid plaque load in the cortex and hippocampus of 15-month-old Tg2576 mice. Low- (LOW) and high- (HI) intensity ET animals ran at speeds of 15 m/min on a level treadmill and 32 m/min at a 10% grade, respectively, for 60 min/day, five days/week, from 3 to 15 months of age. Sedentary mice (SED) were placed on a level, non-moving, treadmill for the same duration. ET mice demonstrated a significantly lower amyloid plaque load in the cortex and hippocampus that was intensity dependent. Improvement in cognitive function, assessed by Morris Water Maze and Novel Object Recognition tests, was greater in the HI group compared to the LOW and SED groups. LOW mice performed better in the initial latency to the platform location during the probe trial of the Morris Water Maze (MWM) test than SED, but not in any other aspect of MWM or the Novel Object Recognition test. The results of this study indicate that exercise training decreases amyloid plaque load in an intensity dependent manner and that high-intensity exercise training improves cognitive function relative to SED mice, but the intensity of the LOW group was below the threshold to demonstrate robust improvement in cognitive function in Tg2576 mice.
在Tg2576小鼠生命早期，三个月的运动训练（ET）以强度依赖的方式降低了可溶性Aβ和Aβ水平（Moore等人，2016年）。在此，我们研究了12个月的低强度和高强度运动训练对15月龄Tg2576小鼠皮质和海马认知功能及淀粉样斑块负荷的影响。低强度（LOW）和高强度（HI）运动训练组的动物分别在水平跑步机上以15米/分钟的速度和在10%坡度下以32米/分钟的速度跑步，每天60分钟，每周五天，从3月龄到15月龄。久坐不动的小鼠（SED）被放置在水平的、不移动的跑步机上相同的时长。运动训练组小鼠在皮质和海马中的淀粉样斑块负荷显著降低，且具有强度依赖性。通过莫里斯水迷宫和新物体识别测试评估，与低强度组和久坐不动组相比，高强度组的认知功能改善更大。在莫里斯水迷宫（MWM）测试的探测试验中，低强度组小鼠到达平台位置的初始潜伏期比久坐不动组小鼠表现更好，但在MWM或新物体识别测试的任何其他方面并非如此。本研究结果表明，运动训练以强度依赖的方式降低淀粉样斑块负荷，相对于久坐不动的小鼠，高强度运动训练可改善认知功能，但低强度组的强度低于在Tg2576小鼠中证明认知功能有显著改善的阈值。
