NYU Neuroscience Institute and Department of Otolaryngology, New York University Langone Medical Center, New York, NY 10016, USA; Center for Neural Science, New York University, New York, NY 10003, USA.
NYU Neuroscience Institute and Department of Otolaryngology, New York University Langone Medical Center, New York, NY 10016, USA; Center for Neural Science, New York University, New York, NY 10003, USA.
Curr Biol. 2023 Nov 6;33(21):4704-4712.e3. doi: 10.1016/j.cub.2023.09.005. Epub 2023 Sep 26.
Bilaterally organized brain regions are often simultaneously active in both humans and animal models, but the extent to which the temporal progression of internally generated dynamics is coordinated across hemispheres and how this coordination changes with brain state remain poorly understood. To address these issues, we investigated the zebra finch courtship song (duration: 0.5-1.0 s), a highly stereotyped complex behavior produced by a set of bilaterally organized nuclei. Unilateral lesions to these structures can eliminate or degrade singing, indicating that both hemispheres are required for song production. Additionally, previous work demonstrated broadly coherent and symmetric bilateral premotor signals during song. To precisely track the temporal evolution of activity in each hemisphere, we recorded bilaterally in the song production pathway. We targeted the robust nucleus of the arcopallium (RA) in the zebra finch, where population activity reflects the moment-to-moment progression of the courtship song during awake vocalizations and sleep, where song-related network dynamics reemerge in "replay" events. We found that activity in the left and right RA is synchronized within a fraction of a millisecond throughout song. In stark contrast, the two hemispheres displayed largely independent replay activity during sleep, despite shared interhemispheric arousal levels. These findings demonstrate that the degree of bilateral coordination in the zebra finch song system is dynamically modulated by behavioral state.
双侧组织化的脑区通常在人类和动物模型中同时活跃，但内部产生的动态的时间进程在多大程度上在半球间协调，以及这种协调如何随大脑状态而变化，这些仍然知之甚少。为了解决这些问题，我们研究了斑胸草雀求偶鸣叫（持续时间：0.5-1.0 秒），这是一种由一组双侧组织化核产生的高度刻板的复杂行为。这些结构的单侧损伤可以消除或降低鸣叫，这表明两个半球都参与了鸣叫的产生。此外，先前的工作表明，在鸣叫期间存在广泛的连贯和对称的双侧前运动信号。为了精确跟踪每个半球活动的时间演变，我们在鸣叫产生途径中双侧记录。我们以斑胸草雀的Arcopallium 坚固核（RA）为目标，其群体活动反映了在清醒发声和睡眠期间求偶鸣叫的瞬间进展，其中与鸣叫相关的网络动态在“回放”事件中重新出现。我们发现，在鸣叫过程中，左右 RA 的活动在几毫秒的分数内是同步的。相比之下，尽管两个半球的唤醒水平共享，但在睡眠期间，两个半球显示出很大程度上独立的回放活动。这些发现表明，斑胸草雀鸣叫系统中的双侧协调程度是由行为状态动态调节的。
