ANATOMICAL CONSIDERATIONS IN COCHLEAR IMPLANTATION

本项目的研究有两个主要目标：1)了解 颞骨的解剖方面，无论是正常的还是病理的， 与人工耳蜗植入相关，以及2)发展理论 基于计算机的耳蜗三维重建模型 为了进一步加深我们对物理和生理的了解 听神经纤维电兴奋的机制 通过植入人工耳蜗术。正常组织的三维重建 人类、猫和大鼠的耳蜗会构成电子解剖学的基础 发生的电流的潜在分布和模式的模型 当耳蜗电刺激时。这一模式将被实施 对于猫和老鼠，以及人类，允许某些形式的测试 这在人类中是不可能的；例如，从单一的听神经记录 纤维，并研究由实验引起的扰动 诱导的耳蜗病。单光纤模型的开发将 与电子解剖模型集成，以实现对 穿过纤维阵列的听神经棘波放电模式。直达的 与这一理论努力相关的是对空间的调查 罗森塔尔管螺旋神经节细胞与神经节细胞的关系 Corti器官的神经支配，尤指在顶端转角处 直接的径向投影是不可能的。的另一个重要方面 在这个项目中要解决的颞骨解剖涉及 人工耳蜗植入后的组织病理学，这将是 通过对已故患者植入的人工耳蜗进行重建进行分析。 这些耳蜗将被切开，植入到位，这将 允许对电极进行准确定位。螺旋线图案 神经节细胞变性将在动物模型中进行研究以揭示 关于退化过程和在人类材料中与 人工耳蜗植入后退化为语音接收。

The studies in this project have two major goals: 1) to understand the anatomical aspects of the temporal bone, both normal and pathological, that are relevant to cochlear implantation, and 2) to develop theoretical computer-based models from three-dimensional reconstructions of the cochlea in order to further our understanding of the physical and physiological mechanisms underlying the electrical excitation of auditory nerve fibers through cochlear implants. Three-dimensional reconstructions of normal human, cat and rat cochleas will form the basis of electro-anatomical models of potential distributions and patterns of current flow that occur when the cochlea is electrically stimulated. The model will be implemented for the cat and rat, as well as the human, to permit some forms of testing that are not possible in humans; e.g., recording from single auditory nerve fibers, and to study the perturbations resulting from experimentally induced cochlear pathologies. The development of single-fiber models will be integrated with the electro-anatomical models to enable predictions of auditory nerve spike discharge patterns across the fiber array. Of direct relevance to this theoretical effort is an investigation of the spatial relationships between spiral ganglion cells in Rosenthal's canal and their innervation of the organ of Corti, particularly in the apical turn where direct radial projections are unlikely. Another important aspect of temporal bone anatomy to be addressed in this project concerns the histopathology that results from cochlear implantation, which will be analyzed by reconstructing implanted cochleas form deceased patients. These cochlea will be sectioned with the implant in place, which will permit accurate localization of the electrodes. Patterns of spiral ganglion cell degeneration will be studied in an animal model to shed light on the degeneration process and in human material to relate the effects of degeneration to speech reception with cochlear implants.