Changes in apical cochlear mechanics after cochlear implantation

项目摘要 声音进入耳蜗会产生沿耳蜗区纵向传播的行波 其中包括科尔蒂的器官。科尔蒂器官通过外毛产生的力量放大行波。 细胞。在这种放大消失的地方，一组被称为人工耳蜗的电极取代了声音刺激 通过电刺激听神经。改进的人工耳蜗将电和声结合在一起 在听力正常的患者中进行刺激。这些组合植入物可以提高性能。 然而，大约一半的联合人工耳蜗接受者经历了剩余的损失 植入后几个月的听证。这种植入引起的听力损失会降低语音识别和 音乐性。 植入引起的听力损失可能有多种相互作用的原因：免疫的、代谢的和机械的。 我们假设植入引起的耳蜗瘢痕形成(纤维化/骨化)干扰了行波。 传播到低频听力部位。听力损失和植入物引起的疤痕之间的联系是 在啮齿动物模型中可见，反映临床结果。然而，没有对机械性能的直接测量 人工耳蜗术对低频听力的影响。 我们将结合我们的专业知识与啮齿动物模型的人工耳蜗植入和使用最新一代 成像干涉技术-光学相干层析成像(OCT)。为了产生首个此类数据，我们 将使用OCT测振仪来表征慢性阻塞性肺疾病患者耳蜗尖的低频机械功能 植入动物体内。然后，我们将使用OCT成像技术制作每个耳蜗内疤痕的3D地图。 结合组织学和机器学习的图像分析，我们将比较 各耳蜗科尔蒂器增宽、调谐、失真、相位和群延迟的疤痕类型。结果是 我们的OCT测振实验将通过计算机模型的耳蜗功能来解释。实验也将是 在急性植入模型中进行，以评估人工耳蜗术对根尖力学的影响 在留下疤痕之前。此外，我们将使用植入前噪声导致听力损失的模型来测试 高频外毛细胞对低频听力的贡献。 我们的多学科团队将为人工耳蜗植入引起的听力损失提供直接的见解，并将使我们能够 来检验疤痕形成假说。该项目将引导研究的途径，以尽量减少或 预防人工耳蜗植入导致的听力损失，并提高受试者的生活质量 植入人工耳蜗术。

Project Summary Sound entering the cochlea induces a longitudinally propagating travelling wave along the cochlear partition which includes the organ of Corti. The organ of Corti amplifies travelling waves via force production by outer hair cells. Where this amplification is lost, an array of electrodes called a cochlear implant replaces sound stimulation with electrical stimulation of the auditory nerve. Improved cochlear implants combine electrical and sound stimulation in patients with some intact hearing. These combined implants lead to improved performance. However, approximately half of combined cochlear implant recipients experience a loss of their remaining hearing months after implantation. This implantation-induced hearing loss reduces speech recognition and musicality. Implantation-induced hearing loss may have multiple interacting causes; immune, metabolic, and mechanical. We hypothesize that cochlear scarring (fibrosis/ossification) induced by implantation disrupts travelling wave propagation to the site of low frequency hearing. Links between hearing loss and implant-induced scarring are seen in rodent models, reflecting clinical findings. However, there are no direct measurements of the mechanical consequences of cochlear implantation for low frequency hearing. We will combine our expertise with rodent models of cochlear implantation and the use of the latest generation of imaging interferometry – optical coherence tomography (OCT). In a bid to produce the first data of its kind, we will use OCT vibrometry to characterize low frequency mechanical function in the cochlear apex of chronically implanted animals. We will then produce a 3D map of the scarring inside each cochlea using OCT imaging. Coupled with histology and machine learning powered image analysis, we will compare the extent, location and type of scarring with organ of Corti gain, tuning, distortion, phase and group delay in each cochlea. The results of our OCT vibrometry experiments will be interpreted by computer models of cochlear function. Experiments will also be conducted in acutely implanted models to assess the effect of the cochlear implant upon apical mechanics prior to scarring. Additionally, we will use a model with noise induced hearing loss prior to implantation to test the contribution of high frequency outer hair cells to low frequency hearing performance. Our multidisciplinary team will offer a direct insight into cochlear implant-induced hearing loss and will allow us to test the scarring hypothesis. This project will guide avenues of research geared towards minimizing or preventing cochlear implant-induced hearing loss, and lead to improved quality of life for the recipients of cochlear implants.