NEURAL CORRELATES OF VOCAL LEARNING IN SONGBIRDS

这项研究的长期目标是了解神经基础 鸣禽在学习鸣唱过程中获得的记忆是如何储存的 大脑;这些记忆如何与听觉经验相互作用， 类固醇激素的影响，以调节反应特性 听觉神经元;以及这些响应特性如何反映或决定 一只鸟会唱什么歌，以及它对歌曲的行为反应。 鸟鸣的习得可能是最接近人类语言的动物模拟 发展 专门的神经结构已经进化到为这两者服务 行为，说话和唱歌都是在早期最容易学会的。 易受影响时期，需要典型的听觉输入， 听觉反馈 此外，在这两种情况下，正常的知觉 发育可能需要正常的运动获得。 的发展都 语言和歌唱受到异常感觉体验的损害，例如， 暂时性传导性听力损失的儿童或年轻时 鸟被阻止听到适当的歌曲模式或听到它的声音。 自己的声音。 对歌曲神经基础的进一步认识 学习可以提供一个模型，说明 专门的行为被存储，访问，并在运动和知觉中使用。 发展，它也可能揭示细胞机制，导致 不正常的早期感觉经验，限制行为发展。 本研究主要集中在鸣唱控制核HVc上。 这 核是成年鸟类产生歌曲所必需的，听觉/运动 它内部的相互作用在歌曲获得过程中可能是重要的。的 具体研究目标是：1）确定解剖学位点， 听觉输入到HVc; 2）确定内部电路， 该核内神经元的亚类的投射;以及3）至 进一步研究感官体验、歌曲产生和类固醇 激素在听觉反应特性的发展中相互作用， HVc神经元 实验将联合收割机的解剖学和 HVc核的电生理学研究，及其输入， 产出 细胞外应用的神经元示踪剂将用于 确定听觉输入的来源、发展和组织， HVc. 细胞内记录和染料填充将被用来找出 HVc中的不同神经元群体如何相互连接， 与其他鸣唱系统的细胞核有联系。 将制定方法， 使鸟在正常的鸣叫期间听不到自己的鸣叫 获得，以及歌曲和选择性听觉的发展 将从行为和电生理学上监测HVc的反应 在这些鸟。

The long-term goals of this research are to understand the neural basis of how memories acquired during song learning are stored in the songbird brain; how these memories interact with auditory experience and the influence of steroid hormones to modulate the response properties of auditory neurons; and how these response properties reflect or determine what songs a bird will sing and how it will respond behaviorally to song. Bird song acquisition is probably the closest animal analog of human speech development. Specialized neural structures have evolved to subserve both behaviors, and both speech and song are most easily learned during an early impressionable period and require species-typical auditory input and auditory feedback. Furthermore, in both instances, normal perceptual development may require normal motor acquisition. The development of both speech and song is impaired by abnormal sensory experience, such as that caused by temporary conductive hearing loss in children or when a young bird is prevented from hearing appropriate song models or from hearing its own vocalizations. Further understanding of the neural basis of song learning may provide a model of how the sensory input required for specialized behaviors is stored, accessed, and used in motor and perceptual development, and it may also uncover the cellular mechanisms that cause abnormal early sensory experience to limit behavioral development. The proposed research focuses on the song-control nucleus HVc. This nucleus is necessary for song production in adult birds, and auditory/motor interactions within it are probably important during song acquisition. The specific aims research are: 1) to determine the anatomical locus of auditory input to HVc; 2) to determine the internal circuitry and projections of sub-classes of neurons within this nucleus; and 3) to investigate further how sensory experience, song production, and steroid hormones interact in the development of auditory response properties of neurons in HVc. The experiments combine anatomical and electrophysiological investigations of nucleus HVc, and of its inputs and outputs. Extracellularly applied neuronal tracers will be used to determine the source, development, and organization of auditory inputs to HVc. Intracellular recording and dye-filling will then be used to find out how different populations of neurons in HVc connect with each other and with cells in other song-system nuclei. Methods will be developed to prevent a bird from hearing itself sing during the normal period of song acquisition, and the development of song and of selective auditory responses in HVc will be monitored behaviorally and electrophysiologically in these birds.