ONTOGENY OF SONG LEARNING CIRCUITS

该提案有两个主要目标：1）更好地了解机制 2）了解电路的变化，带来的声音学习; 声乐学习的敏感期结束。声乐学习是 我们物种最明显的特征，但我们对它知之甚少。 使之成为可能的电路。一组独特的细胞核， 与习得和产生习得歌曲相关的途径 被描述为鸣禽。未发表的评论 实验表明，鸟类听觉器官之间的关系 发声敏感期末期端脑的变化 学习，随着两个主要投影的消失。研究 计划将详细描述解剖和时间过程 在三种鸣禽，斑胸草雀，金丝雀， 和沼泽麻雀，它们学习发声的时间不同。我们 也将测试对听觉体验的操控程度， 社会经验和荷尔蒙--众所周知， 发声学习的敏感期--会影响 在年轻人的听觉通路中观察到的连通性变化 斑马雀。标准顺行（Biocytin，葡聚糖胺）和 逆行（荧光金、荧光珠和霍乱毒素）技术 将用于映射连通性。行为的重要性 研究的听觉区域将通过在其中放置小 注射细胞毒性物质。这项工作与健康有关 研究，因为它试图确定连接和条件， 限制或有利于声乐学习，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 Unpublished observations from this laboratory indicate that the relation between parts of the avian auditory telencephalon changes towards the end of the sensitive period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.