NEURAL DEVELOPMENT IN RELATION TO VOCAL BEHAVIOR

本提案的目的是揭示功能关系 雀形目鸟类的神经解剖学变化与发声学习之间的关系 鸣禽 斑胸草雀的鸣唱行为依赖于雄激素， 通常只有雄性才能生产 声乐发展包括 一个感觉阶段，在此期间，鸟类记住一个歌曲模型， 感觉运动阶段，当鸟类使用听觉反馈来匹配 他们自己的声音来表达这段记忆。 每个阶段都发生在 在雄性斑胸草雀中， 与神经元数量的巨大变化重叠， 控制歌曲的神经区域之间的连接。 的 研究提出了两个具体目标：1）确定如何 歌唱相关脑区解剖学的个体发育变化 影响，或受影响的声乐发展，和2），以 评估或更好地定义特定神经区域在发声中的作用 学习 许多拟议的研究将雇用女性， 在孵化后不久就被类固醇雄性化了 这些 雌性在歌唱区域表现出个体发育的变化， 雄性的那些，当受到雄激素的刺激时会发出歌声。 重要的是，男性化女性的感觉运动学习可能会 通过操纵这些神经变化的时间来抵消这些神经变化， 雄激素暴露 荷尔蒙控制和行为 分析将被用来确定是否关键时期 感觉学习是由雄激素刺激的声音终止 实践，或通过个体发育变化的歌曲相关的神经 地区 行为分析还将用于确定 神经结构的个体发育变化与 感觉运动学习促进歌曲学习。 光镜 分析和顺行氨基酸放射自显影将被使用 以确定雄激素和/或感觉运动学习 增加神经元数量的变化或控制歌曲的投射 原子核。 为了识别歌曲特有的神经变化 学习，雄激素对神经结构的影响将被评估 在男性化的女性中， 学习 最后，电解质和神经化学损伤将 进行，以进一步了解我们的功能作用， 几个歌曲核心。 声音和声音之间惊人的相似性 鸣禽的发育和人类的语言习得 更好地理解歌曲学习的神经机制 可以提供深入了解神经病理学基础的学习 一般的疾病，更具体地说， 语言习得

The aim of this proposal is to uncover functional relationships between neuroanatomical change and vocal learning in passerine songbirds. In zebra finches, song behavior is androgen-dependent, and normally produced only by males. Vocal development involves a sensory phase during which birds memorize a song model, and a sensorimotor phase when birds use auditory feedback to match their own vocalizations to this memory. Each phase occurs during a restricted developmental period which, in male zebra finches, overlaps with dramatic changes in neuron number and connectivity among the neural regions controlling song. The studies proposed have two specific goals; 1) to determine how ontogenetic changes in the anatomy of song-related brain regions influence, or are influenced by vocal development, and 2) to assess or better define the role of specific neural regions in vocal learning. Much of the proposed research will employ females that have been masculinized by steroids shortly after hatching. These females exhibit ontogenetic changes in song regions that mimic those in males, and develop song when stimulated with androgens. Importantly, sensorimotor learning in masculinized females can be offset from these neural changes by manipulating the timing of androgen exposure. Hormonal manipulations and behavioral analyses will be used to determine if the critical period for sensory learning is terminated by androgenic stimulation of vocal practice, or by ontogenetic changes in song-related neural regions. Behavioral analyses will also be used to determine if overlap between ontogenetic changes in neural structure and sensorimotor learning facilitates song learning. Light microscopic analyses and anterograde amino acid autoradiography will be used to determine whether androgens and/or sensorimotor learning augment changes in neuron number or projections of song-control nuclei. In order to identify neural changes unique to song learning, androgenic effects on neural structure will be assessed in masculinized females deafened to prevent sensorimotor learning. Finally, electrolytic and neurochemical lesions will be performed to further our understanding of the functional role of several song nuclei. Striking similarities between vocal development in songbirds and language acquistion in humans argue that a better understanding of neural mechanisms of song learning may provide insight into neural pathologies underlying learning disorders in general, and more specifically, abnormalities in language acquistion.