Coriolis加速度刺激适应豚鼠前庭传出系统神经元活性的变化

目的 探索动物前庭适应产生的神经生理基础。方法 采用胃电图波幅值作为观察植神经反应的指标，利用小剂量、多次重复的Ｃｏｒｉｏｌｉｓ加速度刺激，建立前庭适应动物模型。采用免疫组化染色和显微相对灰度分析方法，观察动物在产生前庭适应前后，以及前庭适应消退后，脑干前庭传出系统神经元细胞活性的变化，及其与胃电图波幅值变化的联系。结果 建模成功豚鼠受到运动刺激时，刺激前后的胃电图波幅相近。在前庭适应的豚鼠身上，其脑干前庭传出系统神经元内胆碱乙酰化酶的含量明显增加；但在前庭适应消退后，这种含量的差别消失。这表明在豚鼠出现适应性时此神经元对于前庭终器感觉细胞的抑制性作用明显增强。结论 脑干前庭传出系统神经元可能通过降低前庭终器感觉细胞向中枢神经系统的信号发放的程度，参与了适应性的产生过程。

The changes of efferent vestibular system neuron activity in Coriolis acceleration habituated guinea pigs

Objective To investigate the mechanism of vestibular habituation. Methods Guinea pig models of vestibular habituation were set up through low dose multirepeated Coriolis acceleration using electrogastrogram (EGG) as a indicator of reaction of autonomic nervous system to the stimulation. The changes of activity of EVS neurons after gaining and vanishing of habituation were observed through immunohistochemistry staining of sections of EVS in brain stem and relative gamma analysis of choline acetyltransferase (ChAT) in EVS neurons. Results In guinea pig moldels with vestibular habituation, the amplitude of EGG showed no significant change during Coriolis acceleration stimulation as compared with that before stimulation. The ChAT content in EVS neurons of habituated animals was significantly higher than that of contrast animals. when the vestiblar habituation was vanished after 8 days of rest, the difference of ChAT content between habituated animals and contrast animals became nonsignificant. Conclusions It is suggested that EVS neurons take part in the course of habituation acquisition through reducing the signals from vestibular end organ cells to CNS.