Effects of glutamate on distortion-product otoacoustic emissions and auditory brainstem responses in guinea pigs

作     者：SUN Qing1,SUN Jian-he1,SHAN Xi-zheng2, LI Xing-qi1 1 Institute of Otorhinolaryngology, Chinese PLA General Hospital, Beijing 100853, China 2 Department of Otorhinolaryngology, General Hospital of Chinese People’s Armed Forces Beijing 100039, China 

作者机构：Institute of Otorhinolaryngology Chinese PLA General Hospital Beijing 100853 China Department of Otorhinolaryngology General Hospital of Chinese People's Armed Forces Beijing 100039 China 

出 版 物：《Journal of Otology》 (中华耳科学杂志（英文版）)

年 卷 期：2008年第3卷第1期

页      面：29-34页

学科分类：1003[医学-口腔医学] 1002[医学-临床医学] 100213[医学-耳鼻咽喉科学] 10[医学] 

主　　题：glutamate distortion product otoacoustic emission auditory brainstem response auditory neuropathy 

摘      要：Objectives To investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate. Methods CM, CAP, DPOAE, and ABR were recorded as indicators of cochlear functions during whole cochlear perfusion. The morphology of the cochlea was studied via transmission electron microscopy. Results There were no significant changes in DPOAE amplitude before and after glutamate perfusion. CM I/O function remained nonlinear during perfusion. ABR latencies were delayed following glutamate perfusion. The average CAP threshold was elevated 35 dB SPL following glutamate perfusion.. The OHCs appeared normal, but the IHCs and afferent dendrites showed cytoplasmic blebs after glutamate perfusion. Conclusions While being a primary amino acid neurotransmitter at the synapses between hair cells and spiral ganglion neurons, excessive glutamate is neurotoxic and can destroy IHCs and spiral ganglion neurons. The technique used in this study can also be used to build an animal model of auditory neuropathy.