Background： Few studies have focused on peripheral nerve conduction during exposure to microgravity. The -6° head-down tilt （HDT） comprises an experimental model used to simulate the space flight environment. ...Background： Few studies have focused on peripheral nerve conduction during exposure to microgravity. The -6° head-down tilt （HDT） comprises an experimental model used to simulate the space flight environment. This study investigated nerve conduction characteristics of rhesus monkeys before and alter prolonged exposure to H DT. Methods： Six rhesus monkeys （3-4 years old） were tilted backward 6° from the horizontal. Nerve conduction studies （NCSs） were performed on the median, ulnar, tibial, and fibular motor nerves. Analysis of variance with a randomized block design was conducted to compare the differences in the NCS belbre and 7, 2 l, and 42 days alter the 6° HDT. Results： The proximal amplitude of the CMAP of the median nerve was significantly decreased at 21 and 42 days of HDT compared with the amplitude before HDT （4.38 ± 2.83 vs. 8.40 ±2.66 mV, F = 4.85, P = 0.013 and 3.30± 2.70 vs. 8.40± 2.66 mV, F = 5.93, P = 0.004, respectively）. The distal amplitude of the CMAP of the median nerve was significantly decreased at 7, 21, and 42 days of HDT compared with the amplitude before HDT （7.28 ± 1.27 vs. 10.25 ± 3.40 mV, F= 4.03, P = 0.039; 5.05 ± 2.01 vs. 10.25 ± 3.40 mV, F = 6.25, P = 0.04; and 3.95 ± 2.79 vs. 10.25 ± 3.40 mV, F = 7.35, F=- 0.01; respectively）. The proximal amplitude of the CMAP of the tibial nerve was significantly decreased at 42 days of HDT compared with the amplitude betbre HDT （6.14± 1.94 vs. 11.87± 3.19 mV, F = 5.02, P = 0.039）. Conclusions： This study demonstrates that the compound muscle action potential amplitudes of nerves are decreased under simulated microgravity in rhesus monkeys. Moreover, rhesus monkeys exposed to HDT might be served as an experimental model for the study of NCS under microgravity.展开更多
目的观察模拟失重对脑认知功能的影响及中药的干预效果。方法 16名志愿者,-6°头低位卧床(head-down bed rest,HDBR)3周前和卧床结束当天起床前各进行一次fMRI实验,包括中性、冲突两种任务模式和事件相关设计。随机分对照组(8人)、...目的观察模拟失重对脑认知功能的影响及中药的干预效果。方法 16名志愿者,-6°头低位卧床(head-down bed rest,HDBR)3周前和卧床结束当天起床前各进行一次fMRI实验,包括中性、冲突两种任务模式和事件相关设计。随机分对照组(8人)、用药组(8人),用药组卧床期间服用自制中药制剂200 mL/d,3周,对照组服用等量安慰剂。结果两组模拟失重前:前扣带回、额叶和丘脑出现显著的激活。模拟失重后(对照组):额叶、前扣带回激活区的范围和信号强度较卧床前显著减少,丘脑激活消失。模拟失重后(用药组):前扣带回出现了显著的激活区,丘脑可见较显著的激活区,右侧额叶额中回小范围激活区。脑激活区范围和信号强度接近模拟失重前状态。结论模拟失重状态对认知功能有明显的影响,中药可以增强相关脑区对认知功能的调控作用。展开更多
文摘Background： Few studies have focused on peripheral nerve conduction during exposure to microgravity. The -6° head-down tilt （HDT） comprises an experimental model used to simulate the space flight environment. This study investigated nerve conduction characteristics of rhesus monkeys before and alter prolonged exposure to H DT. Methods： Six rhesus monkeys （3-4 years old） were tilted backward 6° from the horizontal. Nerve conduction studies （NCSs） were performed on the median, ulnar, tibial, and fibular motor nerves. Analysis of variance with a randomized block design was conducted to compare the differences in the NCS belbre and 7, 2 l, and 42 days alter the 6° HDT. Results： The proximal amplitude of the CMAP of the median nerve was significantly decreased at 21 and 42 days of HDT compared with the amplitude before HDT （4.38 ± 2.83 vs. 8.40 ±2.66 mV, F = 4.85, P = 0.013 and 3.30± 2.70 vs. 8.40± 2.66 mV, F = 5.93, P = 0.004, respectively）. The distal amplitude of the CMAP of the median nerve was significantly decreased at 7, 21, and 42 days of HDT compared with the amplitude before HDT （7.28 ± 1.27 vs. 10.25 ± 3.40 mV, F= 4.03, P = 0.039; 5.05 ± 2.01 vs. 10.25 ± 3.40 mV, F = 6.25, P = 0.04; and 3.95 ± 2.79 vs. 10.25 ± 3.40 mV, F = 7.35, F=- 0.01; respectively）. The proximal amplitude of the CMAP of the tibial nerve was significantly decreased at 42 days of HDT compared with the amplitude betbre HDT （6.14± 1.94 vs. 11.87± 3.19 mV, F = 5.02, P = 0.039）. Conclusions： This study demonstrates that the compound muscle action potential amplitudes of nerves are decreased under simulated microgravity in rhesus monkeys. Moreover, rhesus monkeys exposed to HDT might be served as an experimental model for the study of NCS under microgravity.
文摘目的观察模拟失重对脑认知功能的影响及中药的干预效果。方法 16名志愿者,-6°头低位卧床(head-down bed rest,HDBR)3周前和卧床结束当天起床前各进行一次fMRI实验,包括中性、冲突两种任务模式和事件相关设计。随机分对照组(8人)、用药组(8人),用药组卧床期间服用自制中药制剂200 mL/d,3周,对照组服用等量安慰剂。结果两组模拟失重前:前扣带回、额叶和丘脑出现显著的激活。模拟失重后(对照组):额叶、前扣带回激活区的范围和信号强度较卧床前显著减少,丘脑激活消失。模拟失重后(用药组):前扣带回出现了显著的激活区,丘脑可见较显著的激活区,右侧额叶额中回小范围激活区。脑激活区范围和信号强度接近模拟失重前状态。结论模拟失重状态对认知功能有明显的影响,中药可以增强相关脑区对认知功能的调控作用。
