MLR: GENERATORS, MATURATION & HEARING ASSESSMENT

中延迟响应（MLR）可以用作 低频听力，一种神经功能的测量方法， 更高水平的听觉通路和客观指数 人工耳蜗功能 目前，MLR的临床应用 由于对1）基本的 发电机站点，2）MLR开发，以及3） 听性脑干反应（ABR）和MLR可用于 预测成人和发育中的低频听力损失 科目 该补助金的目的是： (1)确定MLR在缩醛胺中的特定发生器位点 模型使用颅内映射，神经失活技术 和组织学重建 预计这些 程序也将进一步了解抑制 调节MLR的机制。 (2)研究MLR的成熟变化。 在人类中， MLR在生命的头十年中发展。 通过使用 沙鼠，对人类种群进行充分采样的困难 10年以上可以规避。 沙鼠听觉系统 在几个月内完全发育。 有待调查的是 EEG和MLR频谱内容的发育变化 ABR和MLR在预测低频听力中的应用 发展中的动物 据推测，低频 EEG中的噪声掩盖了儿童的MLR。 这项工作是 预期可得出最佳MLR记录策略， 带孩子 (3)探讨ABR和MLR在评估低 高频动物的频率听力（噪声诱导） 听力损失 电生理与 措施（ABR和MLR）和听力配置 损失，由复合动作电位（AP）阈值确定 将被研究和数学描述。 预计 由此产生的方程可用于临床预测 基于电生理测量的行为听力图。 研究将在成年动物中开始，并将继续进行， 发展主题。 类似的方法在人类身上是有问题的 由于很难获得完整的行为和 电生理数据在一个单一的测试会话和明显的 儿童行为测试的局限性。 目标2和3是 设计的目的是使实验动物的数据具有可比性 我们实验室正在进行的人体研究。

The middle latency response (MLR) can be used as a measure of low frequency hearing, a neurologic measure of function of the higher levels of the auditory pathway and an objective index of cochlear implant function. Clinical use of the MLR is currently limited by inadequate understanding of 1) the underlying generator sites, 2) MLR development, and 3) the extent to which the auditory brainstem response (ABR) and MLR can be used to predict low frequency hearing loss in adult and developing subjects. The aims of this grant are: (1) To determine specific generator sites of the MLR in an aminal model using intracranial mapping, neural inactivation techniques and histologic reconstruction. It is expected that these procedures will also further the understanding of inhibitory mechanisms thought to modulate the MLR. (2) To investigate maturational changes in the MLR. In humans, the MLR develops throughout the first decade of life. By using gerbils, the difficulty of adequately sampling a human population over 10 years can be circumvented. The gerbil auditory system develops completely within a few months. To be investigated are developmental changes in spectral content of the EEG and MLR and the use of ABR and MLR to predict low frequency hearing in developing animals. It has been speculated that low frequency noise in the EEG obscures the MLR in children. This work is expected to lead to an optimal MLR recording strategy for use with children. (3) To examine the use of ABR and MLR in the assessment of low frequency hearing in animals with high frequency (noise-induced) hearing loss. The relationship between electrophysiologic measures (ABR and MLR) and the configuration of the hearing loss, as determined by compound action potential (AP) thresholds will be investigated and described mathematically. It is expected that resulting equations can be used clinicallly to predict the behavioral audiogram based on elelctrophysiological measures. Studies will be initiated in adult animals and will continue with developing subjects. A similar approach is problematic in humans because of the difficulty of obtaining complete behavioral and electrophysiologic data in a single test session and the obvious limitations of behavioral testing in children. Aims 2 and 3 are designed so that data on experimental animals will be comparable to ongoing human studies in our laboratory.