中文摘要：

目的 建立一种立体定位注射谷氨酸损伤大鼠耳蜗核的动物模型并观察其损伤特点。方法 采用脑立体定位技术向成年Wistar大鼠右侧耳蜗核注射10mmol／L的谷氨酸2μl，左侧耳蜗核注射等量生理盐水，术后不同时间进行听性脑干反应测试，并用免疫组化方法观察耳蜗核的神经元和神经胶质细胞变化。结果 术前大鼠ABR阈值平均22．23±3．04dB SPL，手术后ABR阈值右侧平均58．24±22．13dB SPL，左侧59．28±22．30dB SPL，较术前明显升高（P〈0．01）。术后第7d，ABR阈值右侧平均49．42±25．17dB SPL，左侧平均45．19±22．45dB SPL，术后10d，ABR阈值右侧平均43．27±17．16dB SPL，左侧平均38．32±16．20dB SPL，右侧与左侧比较差异无显著统计学意义（P〉0．05）。耳蜗核免疫组化结果证实注射点神经元减少，局部形成空腔及坏死灶，神经胶质细胞在坏死灶周围增生，右侧损伤较左侧明显。结论 立体定位注射技术可以建立大鼠耳蜗核的损伤模型，谷氨酸可以加重其听力损伤。听力损失在术后有自恢复的趋势。

英文摘要：

Objective To establish a cochlear nucleus impairment model by orientation injecting exogenous glutamic acid into rat.Mothods Stereotaxic injecting 10 mmol/L glutamic acid 2 μl into right side cochlear nucleus and 0.9% saline 2 μl into left side cochlear nucleus in 20 adult Wistar rats. The changes in the audiology and morphology at different periods before and after surgery were observed by applying the technologies of auditory brainstem response （ABR） and dyeing of neutons and astrocytes. Results The mean threshold of ABR was 22.23±3.04 dB SPL before the surgery. After the surgery it was 58.24±22.13 dB SPL on the right side and 59.28±22.30 dB SPL on the left side, significantly higher than before （ P 〈 0.01）. The mean ABR threshold of 7th day was 49.42±25.17 dB SPL on the right side and 45.19±22.45 dB SPL on the left side;that of 10th day was 43.27±17.16 dB SPL ontbe right side and 38.32±16.20 dB SPL on the left side.It was noted that on the right side it was a little higher than that on the left side after the surgery （ P 〉 0.05）. Cochlear nucleus immunohistochemistry indicated that neurons around the injection point might be diminished. Necrotizing cavums were found with surrounding astrocytes hyperplasia in some cases. The right side cochlear nucleus impairment was heavier than that of the left. Conclusion Stereotaxic injecting glutamic acid can be used to establish a cochlear nucleus imtpairment model. Hearing loss can recovere in part automatically after the surgery.