【作者】 鲁海涛；

【导师】 龚树生；

【作者基本信息】 华中科技大学 ， 耳鼻咽喉头颈外科， 2010， 博士

【摘要】 目的：探讨豚鼠频率特异性SP-CAP及AABR的检测方法及特点;方法：健康豚鼠20只,分成A、B 2组,每组10只。A组采用腹侧进路的方式开放听泡,记录电极放置在圆窗检测SP-CAP。B组记录电极放置在颅顶检测AABR。刺激声频率为0.25、0.5、1、2、4、8KHz短音。结果：成功记录到了频率特异性SP-CAP及AABR。SP波随频率的增加幅值绝对值逐渐减小,并逐渐由负波转为正波。诱导频率特异性ABR的刺激声刺激时程越长AABR频率特异性越好,但波形分化差;刺激声时程越短,AABR波形越好,频率特异性越差。结论：各频率刺激声能诱导出SP-CAP复合波；而要诱导出波形好,频率特异性好的ABR波,需要合理的设置刺激声参数。目的：探讨谷氨酸的耳蜗兴奋毒性；方法：豚鼠分成2组,实验组(20mmol/l谷氨酸灌注组)10只,对照组(人工外淋巴液灌注组)10只。采用全耳蜗灌流的方法,在灌流前和灌流后2小时检测SP-CAP、AABR、CM、EABR等电生理指标的变化。每组5只动物在灌流后观察内外毛细胞形态变化。余下动物在灌流后8小时观察凋亡诱导因子及caspase的表达变化。结果：谷氨酸灌流2小时后,CAP、AABR、EABR阈值升高,SP波由负波转为正波,CM幅值变小,非线性变化仍存在。内毛细胞突触结构破坏,内毛细胞出现空泡样改变。外毛细胞形态无变化。螺旋神经元出现空泡样变化。凋亡诱导因子在螺旋神经元由胞浆进入胞核。谷氨酸灌流后在Corti’s器及螺旋神经节上都未见caspase表达。结论：谷氨酸对耳蜗内毛细胞及螺旋神经元有明显的毒性作用,并可通过AIF诱导螺旋神经元的凋亡。目的：观察DNQX对耳蜗电生理及形态的影响；方法：10只豚鼠采用全耳蜗灌流的方法,在灌流前及灌流DNQX2小时后检测SP-CAP、AABR、EABR、CM等的变化。5只豚鼠观察灌流后内、外毛细胞形态变化,另外5只在灌流后8小时观察capase和凋亡诱导因子的表达变化。结果：CAP、AABR阈值明显升高,EABR、SP、CM未见明显变化。内、外毛细胞和螺旋神经元形态未见明显变化,凋亡诱导因子表达无变化,未见caspase表达。结论：DNQX能拮抗谷氨酸的生理作用,而对耳蜗没有明显的毒性作用。目的：探讨内毛细胞损伤动物模型建模的方法;方法：10只豚鼠采用全耳蜗灌流的方法,灌流20mmol/l谷氨酸和1.98mmol/lDNQX2小时,检测灌流前后SP-CAP、AABR、EABR、CM等的变化。5只豚鼠观察灌流后内、外毛细胞形态变化,另外5只在灌流后8小时观察螺旋神经元上凋亡诱导因子的表达变化。结果:CAP、AABR阈值明显升高,SP波由负波转为正波,CM非线性变化仍存在,EABR阈值无明显变化。内毛细胞有空泡样变。外毛细胞、螺旋神经元形态无改变,凋亡诱导因子表达无变化,未见caspase表达。结论：采用灌流谷氨酸、DNQx混合液的方法能建立损伤在内毛细胞的动物模型。更多还原

【Abstract】 Objective:To investigate the test methods and characteristic of guinea pig’s frequency-specific summating potential-Compound action potential and acoustic auditory brainstem responseMethod:20 healthy guinea pigs were divided into 2 groups (A and B) of 10 each. Bullae of A group were opened by, and recording electrode placed on round window. The recording electrode of B team was on cranial vault. The stimulus auditory frequency was 0.25,0.5,1, 2,4,8KHz tone pip.Results:The frequency-specific SP-CAP and AABR were recording. SP wave gradually changed from negative wave to positive wave with the frequency increasing. When stimulus duration of tone pip was longer, its frequecy-spcific was better, but the waveform of frequency-specific AABR was worse. Otherwise, the stimulus duration was shorter, its frequency-specificity was worse, but the waveform of AABR was better. Conclusion:The frequency-specific stimulus sound can induce SP-CAP complex wave; and in order to inducing a high frequency-specific AABR waves with good waveform, a reasonable parameters of stimulate sound need to set. Objective:To investigate glutamate excitotoxicity on cochlear;Methods:Guinea pigs were divided into 2 groups, the experimental group (20mmol/1 glutamate infusion group=10), the control group (artificial perilymph perfusion= 10). The whole cochlear perfusion method was used. Before and 2 hours after reperfusion SP-CAP, AABR, CM and EABR were detected. Morphology changes of the inner and outer hair cell were observed after perfusion in 5 guinea pigs each group and the left animals were detected apoptosis inducing factor on spiral ganglion 8 hours later after perfusion.Results:2 hours later after reperfusion glutamate, the threshold of CAP, A ABR and EABR increased; SP wave turn to positive from negative wave; CM amplitude got smaller, but non-linear change still existed. Inner hair cell synapses were destructed, and there were vacuolar in inner hair cells. outer hair cell morphology didn’t change. There were vacuolar changes in Spiral neurons. AIF entered into the nucleus from the cytoplasm of spiral neurons.Conclusion:Glutamate have apparent toxic effects in cochlear inner hair cells and spiral neurons, and can induce apoptosis of spiral neurons by AIF.Objective:To observe the effect of DNQX on cochlear electrophysiology and morphology; Methods:DNQX was perfused for 2 hours by the method of the whole cochlear perfusion. SP-CAP, AABR, CM and EABR were testing before and after the perfusion. Morphology changes of the inner and outer hair cell were observed after perfusion in 5 guinea pigs and the left animals were detected apoptosis inducing factor on spiral ganglion 8 hours later after perfusion.Results:CAP, AABR thresholds were significantly increased, EABR, SP and CM no significant change. Inner and outer hair cells and spiral neurons had no significant morphological changes, the expression of AIF were unchanged.Conclusion:DNQX antagonized the physiological role of glutamate, but had no significant toxicity on cochlear function.Objective:To evaluate the modeling method of animal model of inner hair cell damage;Methods:20mmol/1 glutamate and 1.98mmol/lDNQX were perfuse for 2 hours by the method of the whole cochlear perfusion, SP-CAP, ABR, CM and EABR were testing before and after perfusion. Morphology changes of the inner and outer hair cell were observed after perfusion in 5 guinea pigs and the left animals were detected apoptosis inducing factor on spiral ganglion 8 hours later after perfusion.Results:The thresholds of CAP and ABR were significantly increased, but the thresholds of EABR was not; SP wave turned to positive wave from negative wave; CM had no significant changes in amplitude. Inner hair cell showed degeneration and edema. Outer hair cells and spiral ganglion had no change, and AIF were unchanged. Conclusion:The mixture perfusion of glutamate and DNQX can establish animal models with injury inner hair cells.更多还原