颈上神经节切除对豚鼠耳蜗血流及听性脑干反应阈的影响

The Effect of Superior Cervical Sympathectomy on the Cochlear Blood Flow and Auditory Threshold in Guinea Pigs

目的研究豚鼠颈交感神经节对耳蜗血流及听觉生理功能的调节作用。方法在正常豚鼠单侧耳蜗螺旋蜗轴动脉局部滴加逆行追踪剂辣根过氧化物酶(horseradishperoxidase,HRP),观察双侧交感颈上神经节、星状神经节内的阳性神经元分布;建立单侧颈上神经节切除模型,观察术后不同时间点双侧耳蜗血流、听性脑干反应的情况;建立单侧颈上神经节切除后噪声性听损伤模型,观察颈上神经节切除对噪声损伤导致的听觉阈移是否有保护作用。结果耳蜗螺旋蜗轴动脉局部给予逆行追踪剂后同侧颈上神经节内可见阳性神经元;单侧颈上神经节切除1周后,术侧耳蜗底回血管纹处血流较对侧升高,听性脑干反应阈值无明显变化;颈上神经节切除对噪声导致的听损伤有一定的保护作用。结论交感颈上神经节切除对豚鼠耳蜗血流及听觉生理功能有一定的影响。

Objective To investigate the regrlative role of the cervical sympathetic ganglia on the cochlear blood flow and auditory function in guinea pig. Methods The horseradish peroxidase（HRP） was given to spiral modiolar artery locally for retrograde tracing in guinea pig. Immunohistochemical double- labeled technique was used in this study. The cochlear blood flow and auditory brainstem response（ABR） was measured a week after anilateral superior cervical sympathectony. The animal model of superior cervical sympathectomy following noise exposure in guinea pigs was estableshed to observe the auditory threshold shift. Results Retregradely labeled neurons with HRP were found in the ipsilateral superior cervical ganglion（SCG）. Most of HRP- labeled neurons in SCG were tyrosion hydroxylase（TH） positive. The blood flow of the capillaries of the stria vascularis on the experimental side a week ago were more aplenty than that of the opposite side, but the ABR threshold did not changed before and after ablation of the superior cervical ganglion, A protective role against noise injury was observed after surgical ablation of superior cervical ganglion. Conclusion The superior cervical sympathectomy can influence the cochlear blood flow and auditory function in guinea pig.