Subcortical Neural Basis of Hearing

描述(申请人提供)：听觉系统的基本功能是允许听者在安静和嘈杂的环境中检测信号。老年人和听力受损的人在嘈杂环境中探测声音的能力受到影响。在嘈杂的环境中，大脑中信号的表示通过反馈连接得到增强，反馈连接在麻醉和去大脑准备中不是完全功能的，但处于清醒和行为状态。该项目的目标是研究清醒和行为灵长类动物在安静和嘈杂环境中信号的表征。灵长类动物是这项研究的选择，因为它们与人类的系统发育相似，以及灵长类动物和人类脑干的相似性，这与其他哺乳动物不同。先前对猫的研究表明，信号在噪声中的表征可以与接受场的组织和反应特性相关。如果持续的噪音导致 信号表示的降级，然后对噪声的快速适应将增强表示，并且用于表征单元的基本响应特性可以很好地预测噪声中的信号表示质量。该项目建议通过记录清醒和行为灵长类动物的耳蜗核和下丘的单个单位反应来检验这些假设，这些灵长类动物的传出系统是完整和功能的。总体而言，这项研究将有助于确定在高水平噪音中保持我们听力能力的一些机制。

DESCRIPTION (provided by applicant): The basic functional of the auditory system is to allow listeners to detect signals in quiet as well as noisy environments. The ability to detect sounds in noisy environments is compromised in the elderly and the hearing impaired. The representation of signals in noisy environments in the brain is enhanced by feedback connections, which are not fully functional in anesthetized and decerebrate preparations but are in the awake and behaving condition. The goal of this project is to study the representation of signals in quiet and noisy environments in awake and behaving primates. Primates are the choice for this study due to their phylogenetic similarity with humans, as well as the similarity of the primate and human brainstem, which are different from other mammals. Previous studies in cats have shown that the representation of signals in noise can be correlated with receptive field organization and response properties. If sustained noise causes degradation of signal representation, then rapid adaptation to noise would enhance representation, and basic response properties used to characterize a unit may be a good predictor of signal representation quality in noise. This project proposes to test these hypotheses by recoding single unit responses in the cochlear nucleus and inferior colliculus in awake and behaving primates, whose efferent systems are intact and functional. Overall, this study will help determine some of the mechanisms that preserve our ability to hear in high levels of noise.