Connolly Meghan G, Bruce Spencer R, Kohman Rachel A
University of Illinois Urbana-Champaign, Department of Animal Sciences, Champaign, IL, USA.
University of North Carolina Wilmington, Department of Psychology, Wilmington, NC, USA.
Neuroscience. 2022 May 10;490:275-286. doi: 10.1016/j.neuroscience.2022.03.022. Epub 2022 Mar 21.
The physiological effects of exercise vary as a function of frequency and length. However, research on the duration-dependent effects of exercise has focused primarily on young adults and less is known about the influence of exercise duration in the aged. The current study compared the effects of short-term and long-term running wheel access on hippocampal neurogenesis and neuroimmune markers in aged (19-23 months) male C57BL/6J mice. Aged mice were given 24-hour access to a running wheel for 14 days (short-term) or 51 days (long-term). Groups of non-running aged and young (5 months) mice served as comparison groups to detect age-related differences and effects of exercise. Long-term, but not short-term, exercise increased hippocampal neurogenesis as assessed by number of doublecortin (DCX) positive cells in the granular cell layer. Assessment of cytokines, receptors, and glial-activation markers showed the expected age-related increase compared to young controls. In the aged, exercise as a function of duration regulated select aspects of the neuroimmune profile. For instance, hippocampal expression of interleukin (IL)-10 was increased only following long-term exercise. While in contrast brain levels of IL-6 were reduced by both short- and long-term exercise. Additional findings showed that exercise does not modulate all aspects of age-related neuroinflammation and/or may have differential effects in hippocampal compared to brain samples. Overall, the data indicate that increasing exercise duration produces more robust effects on immune modulation and hippocampal neurogenesis.
运动的生理效应会因频率和时长的不同而有所变化。然而，关于运动时长依赖性效应的研究主要集中在年轻人身上，而对于老年人运动时长的影响了解较少。当前的研究比较了短期和长期使用跑步轮对老年（19 - 23个月）雄性C57BL/6J小鼠海马神经发生和神经免疫标志物的影响。老年小鼠可在24小时内使用跑步轮，持续14天（短期）或51天（长期）。不运动的老年和年轻（5个月）小鼠组作为对照组，以检测与年龄相关的差异和运动的影响。通过颗粒细胞层中双皮质素（DCX）阳性细胞的数量评估，长期而非短期运动增加了海马神经发生。细胞因子、受体和胶质细胞激活标志物的评估显示，与年轻对照组相比，出现了预期的与年龄相关的增加。在老年人中，运动作为时长的函数调节了神经免疫特征的某些方面。例如，白细胞介素（IL）-10的海马表达仅在长期运动后增加。而相比之下，短期和长期运动均降低了大脑中IL-6的水平。其他研究结果表明，运动并不会调节与年龄相关的神经炎症的所有方面，和/或与脑样本相比，运动在海马中可能具有不同的作用。总体而言，数据表明增加运动时长会对免疫调节和海马神经发生产生更显著的影响。
