Estimation of the status of spiral ganglion neurons and Schwann cells in the auditory neural degeneration mouse using the auditory brainstem response

Abstract

Conclusion: The auditory brainstem response (ABR) wave I threshold, latency and amplitude are insensitive to spiral ganglion neurons (SGNs) degeneration, but are sensitive to the degeneration of Schwann cells and can estimate the status of Schwann cells in a neural degeneration mouse model. The thorough pre-operative ABR assessment would be helpful in predicting cochlear implant performance.

Objectives: This study aimed in finding a non-invasive electrophysiological method to evaluate the status of the auditory nerve and the Schwann cells in sensorineural hearing loss (SNHL) and auditory neuropathy (AN) ears, and providing useful information for candidates screening and outcome prediction in cochlear implantation.

Methods: The frequency-specific acoustic ABR was recorded in mice. The immunohistochemical staining was performed to detect the SGNs and Schwann cells in mice cochlea. The correlations between ABR wave I metrics and SGNs, Schwann cells were investigated.

Results: In SNHL and AN mice cochlea, statistically significant correlations between ABR wave I thresholds, latencies and amplitudes at 8, 16, and 32 kHz and their corresponding SGNs densities were found only in wave I amplitude at 8 kHz. While the ABR wave I metrics at all three frequencies showed strong significant correlations with their corresponding Schwann cells densities.

Chinese abstract

结论：听觉脑干反应（ABR）波I阈值、潜伏期和波幅, 对螺旋神经节细胞（SGNs）退化没有反应, 但对Schwann细胞退化敏感, 可用于估计神经退化小鼠模型中Schwann细胞的状态。全面的术前ABR评估将有助于预测人工耳蜗的性能。

目的：本项研究旨在寻找一种非创性电子生理学方法来评估感音神经性听力损失（SNHL）和听觉神经疾病（AN）耳中听觉神经和Schwann细胞的状态, 并为受试者筛查和预测人工耳蜗植入的结果提供有用信息。

方法：记录小鼠的频率特定性声学ABR。进行了免疫组织化学染色, 来检测小鼠耳蜗中的SGNs和Schwann细胞。研究了ABR 波I度量与SGNs细胞和Schwann细胞之间的相关性。

结果：在SNHL和AN小鼠耳蜗中, 8 kHz、16 kHz和32 kHz的ABR波I阈值、潜伏期和振幅之间的统计学显著相关性及其相应的SGN密度仅在8 kHz的波I振幅中发现。在所有三个频率的ABR波I度量显示与其相应的Schwann细胞密度有很强的显著相关性。

Keywords:

• Auditory brainstem response
• spiral ganglion neurons
• Schwann cells
• sensorineural hearing loss
• cochlear implant
• mouse

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China and China Education Ministry Scientific Research Foundation for the Returned Overseas Scholars.