ONTOGENY OF SONG LEARNING CIRCUITS

这项提议有两个主要目标：1)更好地了解机制 声乐学习；2)了解电路的变化带来的 声乐学习的敏感期结束。声乐学习是 我们人类最有症状的特征，但我们对此知之甚少 使之成为可能的电路。一组独特的原子核和 与习得歌曲的习得和产生相关的途径 在鸣禽中被描述过。未发表的对此的观察 实验室研究表明，鸟类听觉各部位之间的关系 发声敏感期末期端脑的变化 学习，随着两大预测的消失。研究 计划将提供详细的解剖和时间进程的描述 在三种鸣鸟中，斑雀、金丝雀的这些变化 和沼泽麻雀，它们学习发声的时间不同。我们 还将测试对听觉体验的操纵程度， 社会经验和荷尔蒙--众所周知，它们会影响最终结果 声乐学习敏感期的时间--会影响 年轻人听觉通路中观察到的连通性变化 斑马雀。标准顺行药物(生物细胞素、葡聚糖胺)和 逆行(荧光金、荧光珠和霍乱毒素)技术 将用于映射连接。在行为上的重要性 被研究的听觉区域将通过在其中放置小块来进行测试 注射细胞毒性物质。这项工作与健康有关 研究，因为它寻求确定联系和条件 限制或支持声乐学习，希望这些见解可以 对人类有用。

This proposal has two main goals: 1) to better understand the mechanisms of vocal learning; 2) to understand the circuit changes that bring the sensitive period for vocal learning to an end. Vocal learning is one of the most symptomatic traits of our species, yet we know very little about the circuitry that makes it possible. A distinctive set of nuclei and pathways associated with acquisition and production of learned song has been described in songbirds. Unpublished observations from this laboratory indicate that the relation between parts of the avian auditory telencephalon changes towards the end of the sensitive period for vocal learning, with the disappearance of two major projections. Research planned will give a detailed description of the anatomy and time course of these changes in three species of songbird, the zebra finch, canary and swamp sparrow, that differ in the timing of their vocal learning. We will also test the extent to which manipulation of auditory experience, social experience and hormones -- which are known to influence the end of the sensitive period for vocal learning -- can affect the timing of the changes in connectivity observed in the auditory pathways of young zebra finches. Standard anterograde (Biocytin, dextran amines) and retrograde (fluorogold, fluorescent beads and cholera toxin) techniques will be used to map connectivity. The behavioral importance of the auditory regions studied will be tested by placing in them small injections of cytotoxic substances. This work is related to health studies in that it seeks to identify connections and conditions that restrict or favor vocal learning, with the hope that these insights can be of use in humans.