NOISE AND THE NEURAL REPRESENTATION OF PURE TONES IN THE AUDITORY SYSTEM

噪声与听觉系统中纯音的神经表征

• 批准号: 3732308
• 负责人: BRADFORD J MAY
• 金额: --
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3732308
• 关键词: audiometry; auditory cortex; auditory discrimination; auditory nuclei; behavioral habituation /sensitization; binaural hearing; brain mapping; cats; electrophysiology; environmental adaptation; inferior colliculus; microelectrodes; neural information processing; noise; single cell analysis; stereotaxic techniques

This project will use extracellular electrophysiological recording to study the effects of background noise on the neural representation of pure tone stimuli. Neural responses will be measured in terms of average discharge rates for single units. Dynamic range properties of single-unit responses will be derived from measures of rate-level functions that are obtained in quiet and in the presence of continuous background noise. Dynamic range measures will be sampled in the dorsal cochlear nucleus, inferior colliculus and primary auditory cortex of behaving cats. Inhibitory mechanisms that shape the neural representation of tones in noise at each of these three levels of auditory processing will be described by frequency response maps, responses to bandpass noise, and responses to broad band noise with notched spectra. This research is based on independent observations that inhibitory influences increasingly reduce auditory responses to continuous noise at higher levels of the auditory system. A reduction in noise-driven activity potentially enhances the rate representation of signals that occur in the presence of background noise by decreasing the negative effects of noise adaptation The primary objectives of this proposal are to demonstrate changes in noise adaptation across three levels of auditory processing, to reveal neural inhibitory mechanisms that contribute to changes in noise-driven activity, and to measure the functional consequences of these changes in terms of the quality of neural representations for signals in noise. Although some of these objectives have been addressed in the nervous system of anesthetized and decerebrate cats, a comprehensive analysis of the neural encoding of pure tones in noisy environments has not been performed in behaving cats. Data obtained in behaving cats are critical to our understanding of noise adaptation because anesthesia substantially alters activity of descending efferent projections to the auditory periphery and inhibitory mechanisms at each subsequent level of auditory processing.

该项目将使用细胞外电生理记录来 背景噪声对PURE神经表征影响的研究 音调刺激。神经反应将以平均值的形式测量 单个单位的排污率。单机的动态范围特性 响应将从符合以下条件的费率水平函数的度量中派生 在安静和存在连续背景噪声的情况下获得。 动态范围测量将在耳蜗背核进行采样， 行为猫的下丘和初级听觉皮质。 影响声调神经表征的抑制机制 这三个听觉处理级别中的每个级别的噪声将是 由频率响应图、对带通噪声的响应和 对具有陷波频谱的宽带噪声的响应。这项研究是基于 根据独立观察，抑制性影响日益减少 听觉对较高水平连续噪声的听觉反应 系统。噪声驱动活动的减少可能会提高这一速度 在存在背景噪声时出现的信号的表示 通过减少噪音适应的负面影响 本提案的目的是展示噪声适应方面的变化 在听觉处理的三个层面上，揭示神经抑制 有助于改变噪声驱动的活动的机制，以及 从以下方面衡量这些变化的功能后果 噪声中信号的神经表示的质量。尽管有些人 这些目标已经在麻醉后的神经系统中得到了解决 和去大脑猫，全面分析了猫的神经编码 在嘈杂的环境中，表现良好的猫并没有表现出纯音。 通过猫的行为获得的数据对我们理解噪音是至关重要的 适应，因为麻醉在很大程度上改变了下行活动 向听觉外周的传出投射及其抑制机制 在听觉处理的每一个后续级别。