Behavioral and Neural Analysis of Vocal Plasticity

描述(申请人提供)：鸣禽的发声学习为研究神经系统如何利用基于表现的反馈来校准和维持运动技能提供了一个有用的模型，尤其与人类语音有关。BirdSong提供了一种描述良好和可量化的行为的优势，而这种行为得到了一组离散的和广泛研究的大脑区域的支持。歌曲学习分两个阶段进行，这两个阶段都严重依赖于听力[17，18]。首先，在感官学习的过程中，幼鸟会听并记住成年家教的歌声。然后，在感觉运动学习的一段时间里，他们使用听觉反馈来逐渐完善自己最初杂乱无章的发音，以便逐渐类似于之前记忆的辅导歌曲。正常的歌曲学习需要在早期发育的敏感期有适当的经验，也依赖于成年后的听觉反馈来维持精确校准的声音输出[4]。歌曲和语言在依赖听觉反馈方面的相似之处表明，对歌曲学习的研究可能会为控制发声-运动学习的行为和神经机制提供更全面的见解。此外，我们对鸟类基底节-前脑回路(前前脑通路或AFP)在发声学习中的功能特别感兴趣。这一回路在幼鸟和成年鸟的依赖反馈的鸣唱学习中起着核心作用。由于AFP可以在明确定义的行为的背景下进行机械研究，因此它可能被证明是更普遍地理解基底节功能的一个特别容易处理的模型。在这里，我们建议使用我们在上一个赠款周期下开发的听觉反馈操作技术来扩展我们对鸣禽发声行为如何由经验塑造的研究(目标1)，确定驱动学习的信号如何在大脑中呈现(目标2)，以及它们如何参与基底节电路来改变歌声(目标3)。我们将重点关注孟加拉雀类，这是一种表现出发声学习的一般特性，但似乎特别依赖听觉反馈的物种。鸣禽提供了一个模型，在这个模型中，基于绩效的反馈对定义明确的、可量化的行为的影响可以在机械水平上得到理解。这样的理解将提供对正常学习过程的基本洞察，特别是与言语相关的学习过程，并有助于我们预防和纠正因这些过程功能障碍而产生的残疾。公共卫生相关性我们将使用鸣禽来研究听觉反馈对成人发声学习产生影响的神经机制。这些研究将提供对正常学习过程的基本洞察，特别是与人类语言有关的学习过程，并有助于我们预防和纠正因这些过程功能障碍而产生的残疾。由于发声学习在很大程度上依赖于广泛保守的基底节-前脑回路，因此该系统可能被证明是一个特别容易处理的系统，可以用来研究这种回路在运动控制和学习中的一般功能以及在基底节疾病条件下出现的缺陷。

DESCRIPTION (provided by applicant): Vocal learning in songbirds provides a useful model for studying how performance-based feedback is used by the nervous system in calibrating and maintaining motor skills, with particular relevance to human speech. Birdsong offers the advantages of a well-described and quantifiable behavior that is subserved by a discrete and extensively investigated set of brain regions. Song learning proceeds in two stages, both of which depend critically on hearing [17, 18]. First, during a period of sensory learning, young birds listen to and memorize the song of an adult 'tutor'. Then, during a period of sensorimotor learning, they use auditory feedback to gradually refine their own initially rambling vocalizations so that they progressively resemble the previously memorized tutor song. Normal song learning requires appropriate experience during a sensitive period in early development, and also relies on auditory feedback in adulthood to maintain precisely calibrated vocal output [4]. The similarities between song and speech in their reliance on auditory feedback suggest that investigations of song learning may provide more general insights into the behavioral and neural mechanisms that govern vocal-motor learning. In addition, we are especially interested in the function of an avian basal ganglia-forebrain circuit (the anterior forebrain pathway or 'AFP') in vocal learning. This circuit plays a central role in feedback-dependent song learning in juvenile and adult birds. Because the AFP can be studied mechanistically in the context of well-defined behavior it may prove to be a particularly tractable model for understanding basal ganglia function more generally. Here, we propose to use the techniques for auditory feedback manipulation that we developed under the previous grant cycle to extend our studies of how vocal behavior in songbirds is shaped by experience (aim 1), determine how the signals that drive learning are represented in the brain (Aim 2) and how they engage basal ganglia circuitry to change song (Aim 3). We will focus on the Bengalese finch, a species that exhibits general properties of vocal learning, but appears to rely particularly strongly on auditory feedback. Songbirds provide a model where the influence of performance-based feedback on a well-defined and quantifiable behavior can be understood at a mechanistic level. Such an understanding will provide basic insight into normal learning processes, with particular relevance to speech, and contribute to our ability to prevent and correct disabilities that arise from dysfunction of these processes. PUBLIC HEALTH RELEVANCE We will use songbirds to investigate the neural mechanisms that underlie the influence of auditory feedback on adult vocal learning. Such investigations will provide basic insight into normal learning processes, with particular relevance to human speech, and contribute to our ability to prevent and correct disabilities that arise from dysfunction of these processes. Because vocal learning depends crucially on widely conserved basal ganglia-forebrain circuits, this system additionally may prove an especially tractable one for investigating the general functioning of such circuits in motor control and learning and the deficits that arise under conditions of basal ganglia disease.