模拟失重对大鼠比目鱼肌肌梭神经末梢形态的影响

目的 观察模拟失重对大鼠比目鱼肌肌梭结构和神经支配的影响。方法 采用大鼠尾部悬吊法建立模拟失重模型。雌性大鼠随机分为模拟失重7d，14d，21d组以及对照组。采用肌梭Faworsk氏显示法，光镜观察模拟失重不同时期比目鱼肌肌梭结构和神经末梢形态的改变。结果对照组大鼠比目鱼肌肌梭梭内肌纤维排列整齐，神经末梢完整清晰。模拟失重7d组大鼠肌梭及其神经末梢未见明显改变。模拟失重14d组大鼠梭内肌纤维排列紊乱，神经末梢粗糙模糊。模拟失重21d组肌梭呈现严重的退行性改变，神经末梢溃变，局部断裂，模糊不清，着色变浅。结论 模拟失重可致肌梭的结构和神经支配发生明显的改变，随模拟失重时间延长而加重。

Influence of Simulated Weightlessness on the Morphology of Nerve Endings of Muscle Spindle in Rat Soleus Muscle

Objective To study changes in structure and innervation of soleus muscle spindle in rats induced by simulated weightlessness. Method Weightlessness was simulated by tail suspension in female rats. The technique of Fawosky's Staining was used to detect the morphology of nerve endings of soleus muscle spindle in 7 d, 14 d, 21 d tail suspended and control rats. Result The intrafusal muscle fibers were regular and nerve endings were intact and clear in the soleus spindles of control rats. No obvious change was observed in muscle spindles of 7 d tail suspended rats. Intrafusal muscle fibers became irregular, with rough and vague nerve endings in 14 d tail suspended rats. The distinct retrograde change of muscle spindles and never endings were observed in 21 d tail suspended rats. Degeneration and rupture were found in nerve endings,which made it unclear and pale in staining. Conclusion Simulated weightlessness could induce time related changes in structure and innervation of soleus muscle spindle in rats.