短期和长期训练对小鼠脑局灶缺血后大脑皮质胆碱能纤维密度的影响

Effect of short-term and long-term physical exercise on the density of cholinergic fibers in the cerebral cortex of mice after cerebral focal ischemia

目的:观察小鼠脑局灶缺血后短期和长期运动训练对大脑皮质胆碱能纤维密度的影响。方法:取30只雄性C57BL/6J鼠用Bederson等的方法,建立大脑中动脉闭塞模型,造模后随机分为运动组和对照组各15只。运动组:将小鼠放进直径为17cm的带轴承转笼,让其主动跑笼,第1天跑10min,以后每天增加10min,直至1h/d,共训练90d,每周一到六训练,周日休息;对照组:跑笼固定不转。两组分别在造模后15,90d随机取5只处死,观察两组小鼠大脑皮质Ⅲ,Ⅴ层胆碱能阳性纤维密度(以0.01mm2内阳性纤维与测试线的交点数表示)改变。结果:①造模后15d,两组小鼠缺血侧和正常侧脑皮质Ⅲ层胆碱能阳性纤维密度差异不显著(P>0.05);运动组小鼠脑皮质Ⅴ层缺血侧和正常侧胆碱能阳性纤维密度均高于对照组犤(176.6±15.3),(123.8±15.4)个;(189.8±17.9),(118.6±13.4)个,P<0.05犦。②造模后90d,无论在正常侧还是在缺血侧,无论在脑皮质Ⅲ层还是Ⅴ层,运动组小鼠胆碱能阳性纤维密度均高于对照组(P<0.05)。③脑皮质Ⅲ层、Ⅴ层运动组缺血侧运动90d后比运动15d后小鼠胆碱能阳性纤维密度高(P<0.05),而在对照组两者差异不显著(P>0.05)。脑皮质Ⅲ层、Ⅴ层运动组正常侧运动90d后比运动15d后小鼠胆碱能阳性纤维密度高(P<0.05),而在对照组两者差异不显著(P>0.05)。结论:长期运动训练比短期训练能提高小鼠大脑中动脉闭塞后胆碱能纤维的密度,对大脑两侧均有一定影响。

AIM： To observe impact of short-term and long-time movement training on cholinergic fibers density in cerebral cortex after cerebral focal ischemia of mice.METHODS： Thirty male C57 BL/6J mice underwent middle cerebral artery occlusion （MCAO） （described by Bederson et al） to establish MCAO models, and then randomly divided into training group and control group with 15 in each group. The mice of training group were trained with 17 cm voluntary running wheel for 10 minutes at day 1, and increased by 10 minutes every day until 1 hour a day, for 90 days, training from Monday to Saturday, The running wheel of control group was constant. Fifteen days and 90 days after MCAO, 5 rats from each group, respectively, were killed. Cholinergic fibers density in cerebral cortex Ⅲ and Ⅴ layer （represented by junction amount of positive fibers and test line in 0.01 mm^2） was observed in mice of the two groups. RESULTS： ①There was no significant difference in cholinergic positive fibers in Ⅲ layers in cortex at ischemic side and normal side of mice between training group and control group in 15 days after MCAO （P 〉 0.05）, but it was higher in training group than in control group in Ⅴ layers in cerebral cortex of two sides [（176.6±15.3）, （123.8±15.4） ; （189.8 ±17.9）, （118.6±13.4）,P 〈 0.05]. ②In 90 days after MCAO, it was showed that cholinergic positive fibers density was higher in the training group than that in the control group in Ⅲ and V layers in cerebral cortex in normal and ischemic sides （P 〈 0.05）. ③The cholinergic positive fibers density in the training group in Ⅲ and Ⅴ layers in cerebral cortex in ischemic sides and normal side was higher in 90 days after MCAO than in 15 days （P 〈 0.05）, but there was no significant difference in the control group （P 〉 0.05）. CONCLUSION： The long-term physical training can accelerate the germination of cortical cholinergic fibers than in short-term training, have some roles on the normal and ischemic sides of cerebrum in mice after MCAO.