Modulation of auditory processing for vocal communication

描述（由申请人提供）：语音的听觉处理涉及高级神经计算。在鸣禽中发现了一个实验上可访问的模型系统，该系统使用习得的声音进行声音交流，鸣禽在求偶或攻击行为中使用它们的歌声进行交流。先前的研究揭示了鸣禽大脑中与这些声音信号的听觉处理有关的几个回路。其中之一，前脑通路（AFP），在学习过程中起着至关重要的作用，在这个过程中，幼鸟学会了复制导师的歌声。AFP神经元对复杂的听觉刺激表现出非常选择性的反应，比如鸟自己的歌声或导师的歌声。尽管这些是在任何物种中记录的最具选择性的听觉反应，AFP在听觉处理中的确切作用仍不清楚。我们的工作的长期目标是了解复杂的声音交流的听觉信号是如何在前脑中处理的，以及神经调节剂是如何改变这种处理的。我们的具体假设是，听觉信息仅从白质（皮层样）核HVC进入X区，进一步的加工受到局部GABA和多巴胺的影响。我们认为，多巴胺在BG的释放诱导了对传入的pallial输入的反应减少，从而减少了对歌曲播放的反应。在高多巴胺条件下，BG对目标结构的影响会减弱。

DESCRIPTION (provided by applicant): Auditory processing of speech involves high-level neural computation. An experimentally accessible model system using learned sounds for vocal communication is found in songbirds, which use their songs to communicate during courtship or aggressive behaviors. Previous work revealed several circuits involved in auditory processing of these vocal signals in songbird brains. One of them, the anterior forebrain pathway (AFP), plays a critical role in the learning process, during which a juvenile bird learns to reproduce the song of a tutor. AFP neurons display very selective responses to complex auditory stimuli such as the bird's own song or tutor songs. Although these are among the most selective auditory responses recorded in any species, the precise role of the AFP in auditory processing remains unclear. Our work has the long term goal of understanding how complex auditory signals for vocal communication are processed in the forebrain, and how neuromodulators alter this processing. Our specific hypothesis is that auditory information comes to area X exclusively from the pallial (cortex-like) nucleus HVC and further processing is influenced by local GABA and dopamine. We propose that dopamine release in the BG induces a reduced response to afferent pallial inputs, and thus a reduced response to song playback. The BG would then exert a diminished influence on their target structures in high dopamine condition. PUBLIC HEALTH RELEVANCE: These experiments take advantage of the strong parallels that we have demonstrated between songbird basal ganglia circuits and those of mammals. Together, they address mechanisms of auditory processing of vocal communication signals in basal ganglia structures that underlie learning of a vocal behavior in juveniles and modification of such behavior in adults. The results will guide understanding of the role of the basal ganglia in processing complex auditory stimuli, and could shed light on disorders of vocal communication in which the basal ganglia are implicated, such as autism and Tourette's syndrome.