Corticofugal contributions to auditory perceptual learning

项目总结 练习可以提高对听觉刺激的检测或辨别能力。这一过程称为知觉 学习，促进语言习得和音乐技能的发展，并提高语言能力 听力障碍者的理解能力。以前的研究已经强调了听觉皮质的重要性 在听觉知觉学习中，我们对其所涉及的神经回路机制缺乏完整的了解。 从听觉皮质到皮质下听觉区域的皮质分离投射构成了一个巨大的下降区 路径。这条途径将非感官输入与感官结合在一起，非感官输入对知觉学习至关重要。 并增强皮层下听觉区域对相关刺激的神经反应。停用此功能 皮质分离途径也损害了在困难的、接近阈值的刺激下的感觉任务的学习。加在一起， 现有的证据表明，皮质分离投射在 知觉学习。这一提议的核心假设是知觉训练可以增强 皮质激素对上行听觉通路活动的调节，导致逐渐增强 在作为知觉学习基础的信号检测中。目标1将使用体内电生理学来自由移动， 以动物的行为来确定皮质下神经活动是否存在与学习相关的变化 听觉区域。目标2将调查皮质分离投影是否对获取和/或 维持训练引起的知觉敏感度的改善。AIM 3将使用投影专用纤维 用光度记录评估皮质分离神经元的活动是否与行为改善相关 在知觉学习过程中。拟议中的实验结果将有助于揭示神经回路。 潜在的听觉知觉学习，并可能最终为改善听觉感知的策略提供信息 临床人群。

PROJECT SUMMARY Practice can improve the detection or discrimination of auditory stimuli. This process, called perceptual learning, facilitates language acquisition and the development of musical skills, and improves speech understanding in the hearing-impaired. Previous studies have highlighted the importance of the auditory cortex in auditory perceptual learning, but we lack a complete understanding of the neural circuit mechanisms involved. Corticofugal projections from the auditory cortex to subcortical auditory regions comprise a massive descending pathway. This pathway integrates non-sensory inputs, which are essential to perceptual learning, with sensory information and sharpens neural responses to relevant stimuli in subcortical auditory regions. Inactivation of this corticofugal pathway also impairs learning in sensory tasks with difficult, near-threshold stimuli. Taken together, the existing evidence suggests that corticofugal projections are well-positioned to play an important role in perceptual learning. The core hypothesis of this proposal is that perceptual training strengthens corticofugal modulation of activity in the ascending auditory pathway, leading to gradual enhancements in signal detection that underlie perceptual learning. Aim 1 will use in vivo electrophysiology in freely-moving, behaving animals to determine whether there are learning-related changes in neural activity in subcortical auditory regions. Aim 2 will investigate whether corticofugal projections are necessary for the acquisition and/or maintenance of training-induced improvements in perceptual sensitivity. Aim 3 will use projection-specific fiber photometry recordings to assess if the activity of corticofugal neurons correlates with behavioral improvements during perceptual learning. The findings from the proposed experiments will shed light on the neural circuits underlying auditory perceptual learning and may ultimately inform strategies to improve auditory perception in clinical populations.