MECHANISMS OF INTRACOCHLEAR ELECTRICAL STIMULATION

耳蜗内电刺激的机制

• 批准号: 3094735
• 负责人: WILLIAM REICHTSMEIER
• 金额: $ 86.44万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-12-05 至 1993-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3094735
• 关键词: cochlea; computational neuroscience; electrostimulus

The objective of this program project is to identify and study mechanisms that govern current flow, neural responses and perceptual performance under conditions of intracochlear electrical stimulation. The overall strategy of the research program is reflected in the organization of the five projects, all of which are strongly interrelated. Project I deals with the design, fabrication, and characterization of intracochlear electrodes. An experimental 11-contact array for use Projects III-V will be developed, novel electrode that may provide improved spatial localization of intracochlear current will be designed and characterized, and advanced electrode materials that may carry more electrical charge will be evaluated. Project II deals with the characterization of electrical fields generated by intracochlear electrodes. Finite-element field models of cat and human cochleas will be constructed, and field patterns for clinically- applied and experimental electrodes will be studied. These models will be validated by empirical measurements of current fields in cat cochleas. Project III seeks to identify and study mechanisms governing single-neuron responses to electrical stimuli. Biophysical models of neural response will be developed and evaluated in quantitative studies of single-cell discharge patterns in the auditory nerve and anteroventral cochlear nucleus. Topics to be studied include the effects of changing the spatial geometry of the stimulating current field, correlating neural responses with temporal features of stimulating waveforms, and examining stochastic aspects of neural responses. Project IV deals with the ensemble response of multiple neural elements to electrical stimulation. Models combining the results of field models and single-cell responses will be developed, and their predictions will be evaluated in acute physiological studies that determine neural population responses to electrical signals. Project V investigates psychophysical performance of implanted animals on tasks thought to be encoded at peripheral levels of the auditory system, then conducts physiological studies to record unit activity using the same stimulus paradigms that had been studied behaviorally. Models that attempt to predict perceptual performance from neural responses will be developed and evaluated. All animal studies in Projects III-V will be conducted under conditions of both good and poor spiral ganglion survival. A separate Morphology Core allows all projects to relate findings to details of cochlear anatomy in deafened ears. Likely outcomes of the proposed research include (1) an improved knowledge of patterns of intracochlear current flow and the mechanisms by which electrical current excites auditory neurons, (2) insight into the physiological basis of auditory perceptual performance with cochlear implants, (3) identification of ways to control the spatial extend and temporal fine structure of neural responses, (4) the formulation of biophysically sound approaches to improving speech processors in individual implant patients, and (5) the development of optimized electrode designs for clinical use.

该计划项目的目的是识别和研究机制 控制当前流动，神经反应和感知表现 当球内电刺激的条件。 总体策略 研究计划的反映在五个组织的组织中 项目，所有这些都是密切相关的。 我处理的项目 绘制电极的设计，制造和表征。 一个 将开发用于使用项目III-V的实验性11接触阵列， 新的电极，可以改善的空间定位 对等方内电流将被设计和表征，并高级 可能携带更多电荷的电极材料将是 评估。 项目II涉及电场的表征 由粒内电极产生。 猫的有限元野外模型 将构建人类的耳蜗，以及临床上的现场模式 将研究应用和实验电极。 这些模型将是 通过对CAT Cochleas中当前场的经验测量来验证。 III项目旨在识别和研究控制单神经的机制 对电刺激的反应。 神经反应的生物物理模型 将在单细胞的定量研究中开发和评估 听觉神经和前腹部耳蜗中的放电模式 核。 要研究的主题包括更改空间的效果 刺激电流场的几何形状，将神经反应相关联 具有刺激波形的时间特征，并检查随机 神经反应的各个方面。 IV项目处理合奏的响应 电刺激的多个神经元素。 组合模型 将开发现场模型和单细胞响应的结果， 他们的预测将在急性生理研究中评估 确定神经人群对电信号的反应。 项目v 调查植入动物在任务上的心理物理表现 被认为是在听觉系统的外围级别编码的，然后 进行生理研究以使用相同 在行为上研究的刺激范例。 尝试的模型 为了预测神经反应的感知表现 并评估。 所有动物研究III-V中都将进行 在良好和不良的螺旋神经节生存的条件下。 一个 单独的形态核心使所有项目都可以将发现与详细信息联系起来 耳蜗解剖学中的耳朵中的耳朵。 提议的可能结果 研究包括（1）改进的对学内图模式的知识 电流流量和电流激发的机制 听觉神经元，（2）洞察听觉的生理基础 具有人工耳蜗的感知性能，（3）识别方式 控制神经的空间延伸和时间精细结构 响应，（4）生物物理声音的表述 改善单个植入患者的语音处理器，（5） 开发优化的电极设计供临床使用。