IN SITU ANALYSIS OF INTRACOCHLEAR ELECTRODE POSITION

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。人工耳蜗现在被视为一种有效的临床策略，以加强沟通的深度听力受损。据估计，到目前为止，全世界已有超过15万名患者接受了植入。然而，这种方法的疗效在不同的患者之间差异很大。动物行为学研究同样表明，在植入物性能的心理物理测量中，受试者之间存在显著差异。许多因素被假设在这种变化中起作用。这些因素包括但不限于电极设计和配置、神经存活的总体变化、相对于电极接触的局部神经密度变化、刺激接触在耳蜗内的位置以及电极接触与目标神经元件之间距离的变化。我们研究计划的目标是系统地研究耳蜗内电极位置与植入物性能测量之间的关系。我们在长期（6年以上）经过行为训练并植入NIH-R01的动物身上进行了广泛、长期的行为和电生理测试。（NIH要求我们重新申请佛罗里达大学的拨款，目前正在准备一份竞争性的续期申请）。要确定耳蜗内每个电极接触的精确位置，需要结合多种技术；MRM用于关键的解剖细节，TACT用于精细的电极细节。目前，我们正在与Richard Webber博士（Bowman Gray医学中心，TACT的开发者）和Madhu Nair博士（佛罗里达大学，TACT应用领域的权威）合作，优化TACT成像参数，以便在动物牺牲后对体内和原位阵列进行成像。虽然TACT可以提供植入电极阵列的最高分辨率图像，但它不能成像内耳的精细骨结构和组织。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cochlear implants are now seen as an effective clinical strategy for enhancing communication in the profoundly hearing impaired. Estimates suggest that over 150,000 patients worldwide have been implanted to date. The efficacy of this approach is, however, highly variable across patients. Animal behavioral studies have likewise shown significant inter-subject variability in psychophysical measures of implant performance. Numerous factors have been hypothesized to play roles in this variability. These factors include, but are not limited to, electrode design and configuration, overall variations in neural survival, local variations in neural density relative to electrode contacts, intracochlear location of stimulating contacts and variations in the distance between electrode contacts and the target neural elements. The goal of our reseach program has been to study systematically the relationship between electrode position within the cochlea and measures of implant performance. We have carried out extensive, long-term behavioral and electrophysiological testing in our long-term (6+ years), behaviorally-trained and implanted animals under our NIH-R01.( NIH asked us to recompete the grant from UF and a competing renewal application is currently being prepared). To determine the precise location of each electrode contact within the cochlea requires a combination of techniques; MRM for the critical anatomical details and TACT for the fine electrode details. At present we are working with Dr. Richard Webber (Bowman Gray Medical Center; developer of TACT) and Dr. Madhu Nair (University of Florida; a leading authority on TACT applications) to optimize TACT imaging parameters to image the arrays in vivo and, in situ after the animals have been sacrificed. While TACT can provide the highest resolution images of the implanted electrode array, it is not capable of imaging the fine bony structures and tissues of the inner ear.