Kresge Hearing Research Institute, Department of Otolaryngology, The University of Michigan, 1150 W. Medical Center Dr., Ann Arbor, MI 48109-5648, USA.
Hear Res. 2011 Nov;281(1-2):56-64. doi: 10.1016/j.heares.2011.04.019. Epub 2011 May 10.
Following the onset of sensorineural hearing loss, degeneration of mechanosensitive hair cells and spiral ganglion cells (SGCs) in humans and animals occurs to variable degrees, with a trend for greater neural degeneration with greater duration of deafness. Emergence of the cochlear implant prosthesis has provided much needed aid to many hearing impaired patients and has become a well-recognized therapy worldwide. However, ongoing peripheral nerve fiber regression and subsequent degeneration of SGC bodies can reduce the neural targets of cochlear implant stimulation and diminish its function. There is increasing interest in bio-engineering approaches that aim to enhance cochlear implant efficacy by preventing SGC body degeneration and/or regenerating peripheral nerve fibers into the deaf sensory epithelium. We review the advancements in maintaining and regenerating nerves in damaged animal cochleae, with an emphasis on the therapeutic capacity of neurotrophic factors delivered to the inner ear after an insult. Additionally, we summarize the histological process of neuronal degeneration in the inner ear and describe different animal models that have been employed to study this mechanism. Research on enhancing the biological infrastructure of the deafened cochlea in order to improve cochlear implant efficacy is of immediate clinical importance.
在感音神经性听力损失发生后，人类和动物的机械敏感毛细胞和螺旋神经节细胞（SGC）会发生不同程度的变性，随着耳聋时间的延长，神经变性的趋势更大。耳蜗植入假体的出现为许多听力受损的患者提供了急需的帮助，并已成为全球公认的治疗方法。然而，外周神经纤维的持续退化和随后的 SGC 体变性会降低耳蜗植入刺激的神经靶标，从而降低其功能。人们越来越关注生物工程方法，旨在通过防止 SGC 体变性和/或再生外周神经纤维进入失聪感觉上皮来提高耳蜗植入的效果。我们回顾了在受损动物耳蜗中维持和再生神经的进展，重点介绍了内耳损伤后神经生长因子的治疗能力。此外，我们总结了内耳神经元变性的组织学过程，并描述了用于研究这种机制的不同动物模型。为了提高耳蜗植入的效果，增强聋耳蜗的生物学基础的研究具有直接的临床意义。
