Synaptic mechanisms of learned vocal production in the zebra finch

言语和语言障碍很普遍，影响了近10%的总人口。然而，我们对人类语言的功能和功能障碍的了解是有限的，因为我们缺乏对使声音产生的细胞相互作用的了解。人们可以直接使用鸣鸟来解决发声的电路机制，鸣鸟产生的声音序列与人类语音有几个重要的相似之处。和蹒跚学步的孩子一样，幼年斑马雀只有在经过广泛的练习后，才能形成明确的、刻板的和临时精确的发声。精确发声的确切突触和回路机制尚不清楚，但鸣禽前脑运动核HVC(以前称为高级发声中枢的运动皮质类似物)在习得性发声的产生中起着重要作用。HVC的损伤会导致失语症(不能唱歌)，这种结构的轻微降温会减缓歌曲的计时，这表明HVC可能是歌曲控制途径的重要时钟。这个项目的目的是使用一种创新的新工具来研究在该核团中产生的前运动序列的电路机制，该工具能够对自由移动的自然会唱歌的斑马雀进行细胞内记录。该设备将能够在细胞内和突触水平上进行观察，这是传统的细胞外记录所不可能的。将进行细胞内记录、刺激和示踪研究的组合，以清楚地了解潜在的神经元电路。

Disorders of speech and language are widespread, affecting nearly ten percent of the general population. However, our knowledge of the function and dysfunction of human speech is limited by our lack of understanding concerning the cellular interactions that enable vocal production. One may directly address circuit mechanisms underlying vocalization using the songbird, which produces vocal sequences with several important parallels to human speech. As with toddlers, juvenile zebra finches arrive at a crystallized, stereotyped and temporally precise vocalization only after extensive practice. The exact synaptic and circuit mechanisms for the precise vocalization production are unknown, but the songbird forebrain motor nucleus HVC (a motor cortex analog formerly known as the higher vocal center) plays an important role in the production of learned vocalizations. Lesions to HVC lead to aphasia (inability to sing), and a mild cooling of this structure slows the timing of the song, indicating that the HVC may be acting as an important `clock´ for the song control pathway. The aim of this project is to investigate the circuit mechanisms of the premotor sequences generated in that nucleus using an innovative new tool capable of performing intracellular recordings in freely moving, naturally singing zebra finches. This device will enable observations on an intracellular and synaptic level that are not possible with traditional extracellular recordings. A combination of intracellular recordings, stimulation and tracer studies will be performed to get a clear understanding of the underlying neuronal circuits.