Influence of moderate hearing loss on auditory perception & cortical processing

项目摘要 许多听觉感知技能在很长一段时间内（人类）成熟，直到青少年时期。如果 听力在发育过程中受到干扰，可能会出现长期的听觉缺陷， 语言习得令人惊讶的是，听觉编码特性的成熟支持晚现 知觉技能在很大程度上是未知的;我们所知道的很少，完全是基于麻醉的记录。 动物这也是为什么我们对轻中度听力损失对中枢听觉的影响的理解 成熟不稳定。为了解决这些问题，我将研究清醒动物的功能发育， 第一次，并探索听觉编码特性如何受到感官体验的影响。中央 一种假说认为，在发育过程中，中度听力损失会破坏听觉皮层的编码特性 (ACx)，导致听觉感知表现的可测量的缺陷。有三个相关的目标：AIM 1 将决定发育性传导性听力损失是否会破坏成年沙鼠的感知能力。 动物将被测试两个任务，在人类中，已知有不同的成熟率， 受听力损失的影响。这些包括检测正弦幅度（sAM）和频率调制 (sFM)信号. AIM 2将确定在青少年发育期间进行听觉任务训练是否可以 挽救传导性听力损失动物的正常感知行为。AIM 3将描述 在目标1中检查的感知背后的神经编码特性的正常发展速度，并将 评估这些编码特性是否以与感知缺陷相关的方式受到干扰 在AIM 1中检查。在给药期间，将从清醒动物的ACx获得单个单位记录。 耳蜗成熟后的发育。其主要目标是确定编码属性是否 成熟的速度不同，正如行为研究所表明的那样，并确定sAM或sFM编码是否是 易患早期听力损失。总之，这些数据将提供第一个分析听觉编码在清醒 发展中的动物，并揭示中度听力损失是否会破坏感知技能和编码 支持它们的属性。

PROJECT SUMMARY Many auditory perceptual skills mature over a long time course (in humans), well into the teenage years. If hearing is disrupted during development, there may be long-lasting deficits in auditory perception and language acquisition. Surprisingly, maturation of the auditory coding properties that support late-emerging perceptual skills are largely unknown; what little we do know is based solely on recordings from anesthetized animals. This is also why our understanding of the effect of mild to moderate hearing loss on central auditory maturation is unsettled. To address these issues, I will examine functional development in awake animals for the first time, and explore how auditory coding properties are influenced by sensory experience. The central hypothesis is that moderate hearing loss during development disrupts coding properties in the auditory cortex (ACx), leading to measurable deficits in auditory perceptual performance. There are three related aims: AIM 1 will determine whether developmental conductive hearing loss disrupts the perceptual abilities of adult gerbils. Animals will be tested on two tasks that, in humans, are known to have different rates of maturation and to be affected by hearing loss. These include detection of sinusoidal amplitude (sAM) and frequency modulated (sFM) signals. AIM 2 will determine whether training on an auditory task during juvenile development can rescue normal perceptual behavior in animals reared with conductive hearing loss. AIM 3 will characterize the normal rate of development of neural coding properties underlying the percepts examined in Aim 1, and will assess whether these coding properties are perturbed in a manner that correlates with perceptual deficits examined in AIM 1. Single unit recordings will be obtained from the ACx of awake animals during the period of development that follows cochlear maturation. The broad goals are to determine whether coding properties mature at different rates, as suggested by behavioral studies, and to determine whether sAM or sFM coding is vulnerable to early hearing loss. Together, these data will provide the first analysis of auditory coding in awake developing animals, and reveal whether moderate hearing loss disrupts both perceptual skills and the coding properties that support them.