高频正弦波振动对尾吊大鼠比目鱼肌H反射变化的改善作用  

Ameliorated Effects of High Frequency Sinusoidal Vibration Given to Soleus Muscle on H Reflex in Rats Under Tail Suspension

作　　者：杨威[1] 樊小力[1] 张浩[1] 宋新爱[1] 李强[1] 

机构地区：[1]西安交通大学医学院生理学教研室,陕西西安710061

出　　处：《航天医学与医学工程》2008年第2期88-92,共5页Space Medicine & Medical Engineering

基　　金：国家自然科学基金资助(30070830)

摘　　要：目的本研究旨在进一步观察尾吊大鼠与肌梭兴奋性传入有关的α运动神经元的兴奋性的变化,并探讨高频正弦波振动比目鱼肌能否对这种兴奋性的变化产生影响。方法用大鼠尾部悬吊法建立模拟失重模型。对比目鱼肌施加机械正弦波振动(100Hz,0.3mm)。电刺激坐骨神经,同时记录比目鱼肌肌电图。结果尾吊和高频正弦波振动均不影响H反射幅值在刺激强度增加时的变化趋势。尾吊14d后,大鼠最大运动反应(Mmax)和Hmax与Mmax之比(Hmax/Mmax)明显减小,而在尾吊期间给予高频振动后二者没有显著性差异。结论模拟失重状态下肌梭的传入冲动减少可引起大鼠脊髓运动神经元兴奋性降低。高频正弦波振动比目鱼肌可以提高模拟失重条件下脊髓α运动神经元的兴奋性。Objective To observe the changes in excitability of alpha-motoneuron responding to the muscle spindles afferent excitability in the model rats and explore whether the changes in this excit- ability to be changed as high frequency sinusoidal vibration acted on the soleus muscle. Methods The simulated weightlessness model was created by the tail-suspension. Mechanical vibrations at a frequency of 100 Hz with amplitude of 0.3 mm were acted on soleus muscle. The electromyogram of soleus muscle evoked by electrical stimulation of the sciatic nerve was recorded in control rats and HS rats. Results It was showed that HS and HFV did not influence the tendency of changes in amplitude of H reflex when the stimulation intensity increased. However, after 14-day HS, mean maximal motor response （Mmax） and mean maximal monosynaptic reflex/ Mmax （Hmax/Mmax） both significantly decreased,respectively （P 〈0.05）. While Hmax/Mmax and Mmax of HFV ＋ HS rats were not statistically different from those of the control rats （P 〉 0.05）. Conclusion It is suggested that HS should lead to the decrease in motoneurons excitability which is resulted from the reduction of muscle spindle afferent. HFV acted on soleus muscle of rats can improve the excitability of alphamotoneurons in spinal cord during hindlimb suspension.

关 键 词：失重模拟 高频正弦波振动 单突触反射 比目鱼肌 

分 类 号：R854[医药卫生—航空、航天与航海医学] R852.22[医药卫生—临床医学]