Danish Husain H, Aronov Dmitriy, Fee Michale S
Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, United States of America.
PLoS One. 2017 Jun 15;12(6):e0169568. doi: 10.1371/journal.pone.0169568. eCollection 2017.
Birdsong is a complex behavior that exhibits hierarchical organization. While the representation of singing behavior and its hierarchical organization has been studied in some detail in avian cortical premotor circuits, our understanding of the role of the thalamus in adult birdsong is incomplete. Using a combination of behavioral and electrophysiological studies, we seek to expand on earlier work showing that the thalamic nucleus Uvaeformis (Uva) is necessary for the production of stereotyped, adult song in zebra finch (Taeniopygia guttata). We confirm that complete bilateral lesions of Uva abolish singing in the 'directed' social context, but find that in the 'undirected' social context, such lesions result in highly variable vocalizations similar to early babbling song in juvenile birds. Recordings of neural activity in Uva reveal strong syllable-related modulation, maximally active prior to syllable onsets and minimally active prior to syllable offsets. Furthermore, both song and Uva activity exhibit a pronounced coherent modulation at 10Hz-a pattern observed in downstream premotor areas in adult and, even more prominently, in juvenile birds. These findings are broadly consistent with the idea that Uva is critical in the sequential activation of behavioral modules in HVC.
鸟鸣是一种表现出层次组织的复杂行为。虽然在鸟类皮质前运动回路中对歌唱行为及其层次组织的表征已经进行了一些详细研究,但我们对丘脑在成年鸟鸣中的作用的理解并不完整。通过行为学和电生理学研究相结合的方法,我们试图扩展早期的研究工作,早期研究表明丘脑核葡萄状核(Uva)对于斑胸草雀(Taeniopygia guttata)发出刻板的成年歌声是必要的。我们证实,Uva的完全双侧损伤会在“定向”社交环境中消除歌唱,但发现在“非定向”社交环境中,这种损伤会导致高度可变的发声,类似于幼鸟早期的咿呀学语歌声。对Uva神经活动的记录显示出与音节相关的强烈调制,在音节开始前最大程度地活跃,在音节结束前最小程度地活跃。此外,歌声和Uva活动在10Hz时都表现出明显的相干调制——这种模式在成年下游前运动区域中观察到,在幼鸟中甚至更明显。这些发现与Uva在HVC中行为模块的顺序激活中起关键作用的观点大致一致。