内毛细胞损伤动物模型的建立及其电生理研究

发布时间：2018-01-30 04:00

本文关键词：短音 SP-CAP 声刺激听性脑干反应频率谷氨酸耳蜗灌流电生理内毛细胞外毛细胞螺旋神经元凋亡诱导因子 DNQX 耳蜗灌流电生理内毛细胞外毛细胞螺旋神经元凋亡诱导因子谷氨酸 DNQX 耳蜗灌流电生理内毛细胞　出处：《华中科技大学》2010年博士论文　论文类型：学位论文

【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。
[Abstract]:Objective: to study the detection methods and characteristics of frequency specific SP-CAP and AABR in guinea pigs. Methods: twenty healthy guinea pigs were divided into two groups: group A (n = 10) and group A (n = 10). The recording electrode was placed in the round window to detect the SP-CAP.B group. The recording electrode was placed on the top of the skull to detect the AABR. Results: Frequency-specific SP-CAP and AABR.SP waves decreased gradually with the increase of frequency. The longer the duration of ABR stimulation, the better the frequency specificity of AABR, but the worse the waveform differentiation. The shorter the stimulus duration, the better the AABR waveform and the worse the frequency specificity. Conclusion: the SP-CAP complex wave can be induced by the sound energy of each frequency stimulus, and the sound parameters of the stimulation sound should be set reasonably to induce the ABR wave with good waveform and frequency specificity. Objective: to study the excitotoxicity of glutamate in cochlea. Methods: guinea pigs were divided into two groups: experimental group (n = 10) and control group (n = 10). SP-CAP AABRN CM was detected before and 2 hours after perfusion. The changes of electrophysiological indexes such as EABR. The morphological changes of hair cells were observed in 5 animals in each group. The expression of apoptosis-inducible factor and caspase in the remaining animals were observed 8 hours after perfusion. Results: after 2 hours of glutamate perfusion, the threshold value of AABRN EABR increased and the amplitude of SP wave changed from negative wave to positive wave. The nonlinear change still existed, and the synaptic structure of the inner hair cell was destroyed. There were vacuol-like changes in inner hair cells, no changes in morphology of outer hair cells, vacuol-like changes in spiral neurons, apoptosis inducing factors in the nucleus of spiral neurons from cytoplasm, and glutamic acid perfusion in the Corti's organ. No expression of caspase was found in spiral ganglion. Conclusion: glutamate has obvious toxic effects on cochlear hair cells and spiral neurons, and can induce apoptosis of spiral neurons through AIF. Objective: to observe the effect of DNQX on electrophysiology and morphology of cochlea. Methods 10 guinea pigs were perfused with whole cochlea and SP-CAP AABR EABR was detected before and after perfusion for DNQX2 hours. The changes of CM were observed in 5 guinea pigs and the expression of capase and apoptosis-inducing factor were observed in 5 guinea pigs at 8 hours after perfusion. Results there was no significant change in the AABR threshold of AABR, but no significant changes in the morphology of outer hair cells and spiral neurons, and no change in the expression of apoptosis-inducible factors in SPCM. No caspase expression was found. ConclusionDNQX can antagonize the physiological effect of glutamate, but has no obvious toxicity to cochlea. Objective: to explore the method of modeling the animal model of inner hair cell injury. Methods 10 guinea pigs were perfused with 20 mmol / l glutamic acid and 1.98 mmol / L DNQX for 2 hours, and SP-CAP AABR was measured before and after perfusion. The morphological changes of outer hair cells were observed in 5 guinea pigs and the expression of apoptosis-inducible factors in spiral neurons were observed 8 hours after perfusion in 5 guinea pigs. Results the threshold value of AABR increased significantly from negative wave to positive wave (CM). There was no significant change in EABR threshold, but there was no significant change in the threshold of EABR. The expression of apoptosis-inducible factor and caspase were not changed in spiral neurons. Conclusion: the animal model of inner hair cell injury can be established by perfusing the mixture of glutamate and DNQx.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2010
【分类号】：R764

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