听神经病实验动物模型

Experimental Animal Models with features of Auditory Neuropathy

听神经病的临床听力学特征主要表现在具有正常的耳蜗感受器电位和异常的听性脑干反应波形以及对语言的理解障碍,其病理学改变部位被确定是在周边听觉系统,主要表现在内毛细胞缺损、听神经末梢破坏、听神经纤维脱髓鞘病变、螺旋神经节细胞缺损,或上述一个或几个部位同时发生病变。本文介绍了模拟听神经病的各种实验动物模型,其中包括模拟单纯内毛细胞缺损的Slc19a2基因缺陷小鼠和Ggt1基因缺陷小鼠实验模型;模拟单纯Ⅰ型传入神经末梢损害的谷氨酸盐实验模型;模拟单纯脱髓鞘病变的甘油实验模型;模拟Ⅰ型螺旋神经节及其神经纤维损害的乌苯酐实验模型和免疫性疾病损害模型;模拟单纯神经纤维脱髓鞘病变的胆红素实验模型和髓鞘缺陷仓鼠模型;模拟单纯听神经近端脱髓鞘病变的阿霉素模型和压力夹伤听神经实验模型;以及模拟整个周边听觉系统全程病变的卡铂南美栗鼠实验模型。这些实验模型可以分别用于模拟听神经病的一种或几种临床表现及病变特征的实验研究。

Clinically, auditory neuropathy is characterized by normal or near normal otoacoustic emissions, audiomet- tic thresholds and cochlear microphonic potentials, but abnormal or absent auditory brainstem response waveforms and cen- tral auditory processing deficits such as poor speech perception, difficulty hearing in noise and poor temporal processing. The pathological changes underlying auditory neuropathy are believed to originate from the inner hair cells-auditory nerve system and may involve missing inner hair cells, synaptic dysfunction between the inner hair cell and type I auditory neurons, and de- generation or demyelination of auditory nerve fibers that project to the cochlear nucleus. This paper describes various experi- mental animal models that have been developed to mimic certain aspects of auditory neuropathy. These include animal mod- els with missing inner hair cell induced by deletion of the Slc19a2 or Ggt1 genes, degeneration of type I afferent terminals by glutamate excitotoxicity, demyelination of auditory nerve fibers by adriamycin, hyperbilirubin and glycerin, surgical compres- sion of the auditory nerve, autoimnmne diseases, and carboplatin-induced degeneration of inner hair cells and type I auditory nerve fibers in chinchillas. These different experimental models have provided unique insights of auditory function and simu- late different clinical manifestations and pathological features of auditory neuropathy.