Neuropharmacology：科学证实运动如何减轻压力

佰通生物

原文地址链接:Neuropharmacology：科学证实运动如何减轻压力   更多精彩新闻请点击官网：佰通生物

去健身房有诸多原因，不过现在发现健身也可以提高渡过难关的能力。在最近的一系列实验中，University of Georgia的神经科学家们发现了长期紧张的放松和运动之间的联系。这项研究发表在二月版的Neuropharmacology，揭示了一个甘丙肽在这联系中扮演的角色。

“压力，即使只是简单的压力都能降低突触形成，”研究小组的Philip Holmes教授表示，“我们想要证明甘丙肽是干什么的，运动是有何作用，是否前额叶皮层能维持神经可塑性。”前额叶皮层负责复杂的认知行为，如规划，决策，情绪调节和压力恢复。有趣的是，大脑的这一区域会在抑郁的时候萎缩。为了测量突触的形成，科研人员计算了前额叶皮层神经元树突棘。计算之后他们发现树突棘有动态变化，那些久坐不动的老鼠树突棘比经常运动的或给予甘丙肽注射的大鼠更少。

研究人员使用温和的足部冲击和加形迷宫来测量老鼠焦虑行为。运动过的大鼠或者接收甘丙肽注射的大鼠更愿意去探索迷宫。然后研究人员大鼠药物，以阻断甘丙肽的作用。随后发现这些大鼠即使锻炼之后都尽可能久坐而不去探索迷宫。

研究证明，在动物模型中，甘丙肽保护了由压力引起的退化的神经元。甘丙肽被阻断的大鼠运动过后，表现依然焦虑。研究人员还发现，甘丙肽能反转大鼠久坐的负面影响。解剖证据表明，甘丙肽通过保留突触可塑性，或使神经连接随时间变化得到加强或减弱的方式来维持应变。

越来越多的证据指向神经可塑性的缺乏与压力有关的疾病如抑郁症和焦虑的发展有关。而这个研究证明了锻炼确有保护作用，而且这个作用与甘丙肽相关。

DOI: 10.1016/j.neuropharm.2015.02

Galanin mediates features of neural and behavioral stress resilience afforded by exercise
N.R. Sciolino, J.M. Smith, A.M. Stranahan, K.G. Freeman, G.L. Edwards, D. Weinshenker, P.V. Holmes

Abstract
Exercise promotes resilience to stress and increases galanin in the locus coeruleus (LC), but the question of whether changes in galanin signaling mediate the stress-buffering effects of exercise has never been addressed. To test the contributions of galanin to stress resilience, male Sprague Dawley rats received intracerebroventricular (ICV) cannulation for drug delivery and frontocortical cannulation for microdialysis, and were housed with or without a running wheel for 21d. Rats were acutely injected with vehicle or the galanin receptor antagonist M40 and exposed to a single session of either footshock or no stress. Other groups received galanin, the galanin receptor antagonist M40, or vehicle chronically for 21d prior to the stress session. Microdialysis sampling occurred during stress exposure and anxiety-related behavior was measured on the following day in the elevated plus maze. Dendritic spines were visualized by Golgi impregnation in medial prefrontal cortex (mPFC) pyramidal neurons and quantified. Exercise increased galanin levels in the LC. Under non-stressed conditions, anxiety-related behavior and dopamine levels were comparable between exercised and sedentary rats. In contrast, exposure to stress reduced open arm exploration in sedentary rats but not in exercise rats or those treated chronically with ICV galanin, indicating improved resilience. Both exercise and chronic, ICV galanin prevented the increased dopamine overflow and loss of dendritic spines observed after stress in sedentary rats. Chronic, but not acute M40 administration blocked the resilience-promoting effects of exercise. The results indicate that increased galanin levels promote features of resilience at both behavioral and neural levels.