Glutamate（Glu） is the major afferent excitatory neurotransmitter in the auditory system, and excessive Glu may play an important role in cochlear dysfunction. It is unclear how excessive Glu plays roles in cochlear dysfunction in cochlear organotypic cultures. In this study neonatal rat cochlear organotypic cultures were prepared, and then the cochlear tissues were incubated with a new medium containing specific concentrations of Glu（0.1, 0.5, 1, 10 or 20 mmol/L） for 24 h, or incubated with the medium containing a concentration of 20 mmol/L Glu for 6, 12, 24 or 72 h, respectively. It was found that when the cochlear tissues were cultured for 24 h, the inner hair cells（IHCs） were damaged at the concentration of 0.5 mmol/L Glu, and with the increases of the concentrations, the injury was gradually aggravated, and 20 mmol/L Glu resulted in the significant loss of IHCs. In the 20 mmol/L Glu groups, the stereocilia bundles were missing or disarrayed on a few IHCs after culture for 6 h and the damage effect was time-dependent. The missing of IHCs was more significant in the basal turn of the cochlea than in the middle turn of the cochlea under the same concentration of Glu exposure. These results suggest that excessive exogenous Glu affects the morphology of IHCs, but not affects the outer hair cells（OHCs） in cochlear organotypic cultures, and the excitotoxic effects are different on IHCs of different parts of the cochlea under the same concentration of Glu exposure.
目的比较短声和短音诱导的SP-AP电位。方法20只豚鼠分为2组,每组10只,分别采用短声和短音刺激,用圆窗电极记录SP-AP复合波。结果两种刺激声都能较好地诱导出SP-AP复合波。在1、2、4、8 kHz短音诱导的SP-AP波形较好,刺激声强度为100 dB SPL时,各频率短音诱导的SP波振幅分别为-13.56±8.7、-16.61±10.53、-10.13±14.75、-3.71±14.49μv;短声诱导的SP波振幅为-4.44±10.81μv。结论短音能成功诱导出SP-AP波,且具有频率特异性。
