Fahimi Atoossa, Baktir Mehmet Akif, Moghadam Sarah, Mojabi Fatemeh S, Sumanth Krithika, McNerney M Windy, Ponnusamy Ravikumar, Salehi Ahmad
VA Palo Alto Health Care System, 3801 Miranda Ave, Palo Alto, CA, 94304, USA.
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA, 94304, USA.
Brain Struct Funct. 2017 May;222(4):1797-1808. doi: 10.1007/s00429-016-1308-8. Epub 2016 Sep 29.
While it has been known that physical activity can improve cognitive function and protect against neurodegeneration, the underlying mechanisms for these protective effects are yet to be fully elucidated. There is a large body of evidence indicating that physical exercise improves neurogenesis and maintenance of neurons. Yet, its possible effects on glial cells remain poorly understood. Here, we tested whether physical exercise in mice alters the expression of trophic factor-related genes and the status of astrocytes in the dentate gyrus of the hippocampus. In addition to a significant increase in Bdnf mRNA and protein levels, we found that 4 weeks of treadmill and running wheel exercise in mice, led to (1) a significant increase in synaptic load in the dentate gyrus, (2) alterations in astrocytic morphology, and (3) orientation of astrocytic projections towards dentate granule cells. Importantly, these changes were possibly linked to increased TrkB receptor levels in astrocytes. Our study suggests that astrocytes actively respond and could indeed mediate the positive effects of physical exercise on the central nervous system and potentially counter degenerative processes during aging and neurodegenerative disorders.
虽然已知体育活动可以改善认知功能并预防神经退行性变，但其这些保护作用的潜在机制尚未完全阐明。有大量证据表明体育锻炼可改善神经发生和神经元维持。然而，其对神经胶质细胞的可能影响仍知之甚少。在此，我们测试了小鼠的体育锻炼是否会改变海马齿状回中营养因子相关基因的表达以及星形胶质细胞的状态。除了脑源性神经营养因子（Bdnf）mRNA和蛋白水平显著增加外，我们发现小鼠进行4周的跑步机和跑轮运动后，导致（1）齿状回突触负荷显著增加，（2）星形胶质细胞形态改变，以及（3）星形胶质细胞突起朝向齿状颗粒细胞的方向改变。重要的是，这些变化可能与星形胶质细胞中TrkB受体水平升高有关。我们的研究表明，星形胶质细胞会积极响应，并且确实可能介导体育锻炼对中枢神经系统的积极作用，并可能对抗衰老和神经退行性疾病过程中的退行性变化。
