MLR: GENERATORS, MATURATION & HEARING ASSESSMENT

中等延迟响应(MLR)可用作衡量 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标 人工耳蜗植入功能。目前MLR的临床应用 受限于对1)潜在原因的不充分理解 发电商场地，2)MLR开发，以及3)以下程度 听性脑干反应(ABR)和MLR可用于 成人低频听力损失及其发展的预测 研究对象。这笔赠款的目的是： (1)确定氨基酸中MLR的特定发生部位 使用颅内标测、神经失活技术的模型 和组织学重建。预计这些 程序也将加深对抑制性疾病的理解 被认为是调节MLR的机制。 (2)研究MLR的成熟变化。在人类身上， MLR在生命的第一个十年中发展。通过使用 沙鼠，对人类种群进行充分抽样的困难 超过10年可以被规避。沙土鼠听觉系统 在几个月内完全发展。将接受调查的有 脑电和MLR频谱含量的发育性变化 ABR和MLR在低频听力预测中的应用 发育中的动物。据推测，低频 脑电中的噪声掩盖了儿童的MLR。这项工作是 预计将导致使用最佳的MLR记录策略 和孩子在一起。 (3)研究ABR和MLR在低血压评估中的应用 高频(噪声诱发)动物的频率听力 听力损失。电生理学与心理健康的关系 措施(ABR和MLR)和听证的配置 由复合动作电位(AP)阈值确定的损失 将被用数学方法进行调查和描述。这是意料之中的 所得到的方程可用于临床预测 基于电生理测量的行为听力图。 研究将在成年动物身上启动，并将继续 发展中的学科。类似的方法在人类身上也是有问题的 因为很难获得完整的行为和 单次测试中的电生理数据和显而易见的 儿童行为测试的局限性。目标2和目标3是 旨在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.