Effect of Sensorineural Hearing Loss on the Neural Coding of Spatial Hearing

感音神经性听力损失对空间听力神经编码的影响

• 批准号: 9812883
• 负责人: MITCHELL LEE DAY
• 金额: $ 45.3万
• 依托单位: OHIO UNIVERSITY ATHENS
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-16 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9812883
• 关键词: Acoustic Nerve; Acoustics; Adult; Affect; Age; Algorithms; American; Anesthesia procedures; Animal Model; Auditory; Auditory Brainstem Responses; Behavioral; Binaural; Brain; Brain Stem; Cell Count; Cell Nucleus; Cell physiology; Cochlea; Code; Comprehension; Computer Simulation; Confocal Microscopy; Cues; Data; Development; Ear; Environment; Evoked Potentials; Exposure to; Frequencies; Future; Hair Cells; Hearing; Hearing Aids; Hearing Tests; Human; Impairment; Individual; Inferior Colliculus; Label; Laboratories; Location; Loudness; Mammals; Measures; Microscope; Modeling; Nerve Fibers; Neurons; Neurosciences; Noise; Oryctolagus cuniculus; Outer Hair Cells; Performance; Peripheral; Physiological; Population; Positioning Attribute; Protocols documentation; Research; Research Assistant; Sensorineural Hearing Loss; Sound Localization; Source; Speech; Structure; Testing; Time; auditory nuclei; auditory stimulus; awake; base; behavior measurement; cell injury; cochlear synaptopathy; experimental study; hearing impairment; hidden hearing loss; improved; normal hearing; otoacoustic emission; permanent hearing loss; relating to nervous system; response; signal processing; sound; transmission process; undergraduate research; undergraduate student

PROJECT SUMMARY Sensorineural hearing loss (SNHL) is the most common form of permanent hearing loss, often caused by cumulative exposure to loud sounds. Individuals with SNHL have a well-known reduced sensitivity to sound, but lesser-known are the deficits in the abilities to both localize sound sources and use binaural cues to aid sound source detectability and intelligibility in noisy environments. Most mammals, including humans, localize the azimuth (horizontal position) of sound sources by identifying differences in the intensity and arrival time of sound waves at the two ears, known as interaural level and time differences (ILD and ITD), respectively. Neural sensitivity to ITD and ILD first arises in auditory brainstem nuclei that project to the central nucleus of the inferior colliculus (IC). The purpose of the project is to determine the effect of SNHL on the neural representation of sound source azimuth in the central nucleus of the IC. A model of SNHL will be developed in Dutch-belted rabbits, a species with a comparable audiogram to humans. SNHL will be induced in rabbits under anesthesia via overexposure to loud noise. Changes in cochlear function will be quantified by measuring the post-exposure shift in threshold sound level necessary to evoke either the auditory brainstem response (ABR), whose earliest component arises from the auditory nerve, or distortion product otoacoustic emissions (DPOAE), which are related to cochlear outer hair cell function. Threshold shifts in ABRs and DPOAEs will be compared to post- exposure changes in the number of inner and outer hair cells in the cochlea, measured with immunofluorescent labeling under a confocal microscope. Sound-evoked responses of single neurons in the central nucleus of the IC will be measured in and compared between awake rabbits with or without noise-induced SNHL. The sensitivity of each neuron will be measured to sound source frequency, level, azimuth (ITD and ILD co-varying together) and ITD alone. The information about sound source azimuth transmitted by IC neurons will be computed using information-theoretic and population decoding analyses. IC neurons from rabbits with SNHL are predicted to transmit less information about sound source azimuth than those of normal-hearing rabbits. Mechanisms of potential disruption of binaural coding in the IC will be investigated using signal processing models of the IC based on known effects of SNHL on auditory nerve fiber responses.

项目摘要 感官听力损失（SNHL）是最常见的永久性听力损失形式，通常是由 累积暴露于大声的声音。患有SNHL的人对声音的敏感性降低，但是 鲜为人知的是能力的缺陷，既可以定位声音来源并使用双耳线索来帮助声音 噪音环境中的源可检测性和清晰度。包括人类在内的大多数哺乳动物都将 通过识别声音的强度和到达时间的差异，声源的方位角（水平位置） 两只耳朵的波（分别称为耳朵层和时间差异（ILD和ITD））。神经 对ITD和ILD的敏感性首先是在听觉脑干核中引起的，该核将其投射到下部的中心核 胶囊（IC）。该项目的目的是确定SNHL对神经表示的影响 IC的中央核中的声源方位角。 SNHL的模型将以荷兰语开发 兔子，一种与人类相当的听力图的物种。 SNHL将在麻醉下诱导兔子 通过过度暴露于大声噪音。人工耳蜗功能的变化将通过测量暴露后来量化 唤起听觉脑干响应所需的阈值声音级别（ABR），其最早 成分由听觉神经或失真产物耳声排放（DPOAE），是 与人工耳蜗外毛细胞功能有关。将将ABR和DPOAE的阈值转移与后的阈值相比 通过免疫荧光测量的耳蜗中内毛细胞和外部毛细胞数量的暴露变化 在共聚焦显微镜下标记。单个神经元在中央核中的声音诱发反应 IC将在具有或没有噪声诱导的SNHL的清醒兔子之间进行测量和比较。灵敏度 每个神经元的声音源频率，水平，方位角将测量（ITD和ILD共同变化） 一个人。 IC神经元传输的有关声源方位角的信息将使用 信息理论和人口解码分析。预计来自带有SNHL兔子的IC神经元将 与正常听觉兔子相比，传递有关声源方位角的信息更少。机制 将使用IC的信号处理模型研究IC中双耳编码的潜在破坏 基于SNHL对听觉神经纤维反应的已知影响。