跑台联合抓小丸训练促进脑缺血大鼠皮层树突重塑

Treadmill combined with single pellet grasping promotes cortical dendrite remodeling in cerebral ischemia rats

目的:探讨跑台联合抓小丸训练(SPG)对大脑中动脉栓塞(MCAO)大鼠运动皮层树突重塑及前肢运动功能的影响。方法:40只成年雄性SD大鼠,随机分为单纯损伤组(MCAO),跑台训练组(Exercise),小丸抓取组(SPG),联合训练组(S+E)。选用MCAO方法制备大鼠缺血性脑损伤模型,Exercise组接受跑台训练,SPG组接受小丸抓取训练,联合组同时接受两种训练,持续4周。对患侧前肢进行行为学检测,观察动物运动功能恢复情况。伤后5周,使用Golgi-Cox染色检测树突形态和树突生长情况,同时对树突生长相关蛋白神经元素2(NGN2)和突触素Ⅰ(SYNI)进行Western Blot检测。结果:行为学检测结果显示,各组大鼠的右前肢食物抓取率在训练后有不同程度的增加,其中联合训练组的恢复最为明显(P<0.01),动物患侧前肢步行功能在跑台训练组及联合训练组改善更为明显(P<0.05)。Golgi-Cox染色显示,训练4周后单一训练及联合训练组患侧运动皮层区神经元树突复杂性高于MCAO组(P<0.01)。Western Blot结果显示,训练4周后单一训练及联合训练组患侧运动皮层区NGN2和SYNI表达水平增加(P<0.05)。结论:跑台训练联合抓小丸训练能够更有效促进MCAO大鼠运动皮层树突重塑,改善肢体运动功能。

Objective: To investigate the effects of treadmill combined with single pellet grasping training(SPG) on dendrite remodeling of motor cortex and forelimb motor function in middle cerebral artery occlusion(MCAO) rats. Methods: Forty adult male SD rats were randomly divided into MCAO group, Exercise group, SPG group, and S+E group. The MCAO method was used to prepare the ischemic brain injury model in rats. The Exercise group received treadmill training, the SPG group received single pellet grasping training, and the combined group received both kinds of training for 4 weeks. Behavioral test was performed on the affected forelimb to observe the recovery of motor function. Five weeks after injury, the morphology and growth of dendrites were detected by Golgi-Cox staining, and the dendrite growth-related protein Neurogenin-2(NGN2) and Synapsin I(SYNI) were detected by Western Blot. Results: The results of behavioral test showed that the food grasping rate of right forelimb of rats in each group increased to varying degrees after training, and the recovery was most obvious in the combined training group(P<0.01), the improvement of forelimb walking function was more obvious in treadmill training group and combined training group(P<0.05). Golgi-cox staining showed that the complexity of neuron dendrite in the affected motor cortex was higher in the single and combined training groups than in the MCAO group(P<0.01). Western Blot showed that the expression levels of NGN2 and SYNI in the affected motor cortex increased in the single and combined training groups after 4 weeks of training(P<0.05). Conclusion: Treadmill training combined with single pellet grasping training can effectively promote the dendrite remodeling of motor cortex and improve limb motor function in MCAO rats.