Central contributions to acoustic variation in birdsong.
Central contributions to acoustic variation in birdsong.
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DOI：
10.1523/jneurosci.2448-08.2008
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发表时间：
2008-10-08
影响因子：
5.3
通讯作者：
Brainard, Michael S.
中科院分区：
文献类型：
--
作者：
Sober, Samuel J.;Wohlgemuth, Melville J.;Brainard, Michael S.
鸟叫是一种习得的行为，以其高度的刻板印象而著称。尽管如此，成年鸟类在单个歌曲元素或音节的结构上表现出实质性的变化。“之前的研究表明，这种变化中的一些是由鸟类基底神经节回路主动产生的，用于运动探索。”然而，尚不清楚运动前活动的自然变化是否以及如何驱动音节结构的变化。在这里，我们记录了孟加拉雀的运动前核RA（弓形肢强健核），并测量了神经活动是否随音节结构在多个音节重读中的共同变化。我们发现，在大约四分之一的情况下，运动前活动的变化与音节的声学特征（音高、振幅和谱熵）的变化显著相关。在这些情况下，单个神经记录预测8.5 +/ - 0.3%（平均+/ - S.E.）的行为变化，在某些情况下，声学输出的每次试验变化占25%或更多。神经元行为相关性的普遍性和强度表明，每个声学特征都是由一个大的神经元集合控制的，这些神经元以协调的方式改变它们的活动。此外，我们发现与音高（而不是其他特征）的相关性在符号中主要是正相关的，这支持了基于发声运动器官的解剖学和生理学的音高产生模型。总的来说，我们的结果表明，在RA水平上，光谱结构的逐次变化确实受到中枢神经的控制，这与这种变化反映运动探索的观点是一致的。
Birdsong is a learned behavior remarkable for its high degree of stereotypy. Nevertheless, adult birds display substantial rendition-by-rendition variation in the structure of individual song elements or ‘syllables.’ Previous work suggests that some of this variation is actively generated by the avian basal ganglia circuitry for purposes of motor exploration. However, it is unknown whether and how natural variations in premotor activity drive variations in syllable structure. Here, we recorded from the premotor nucleus RA (robust nucleus of the arcopallium) in Bengalese finches and measured whether neural activity co-varied with syllable structure across multiple renditions of individual syllables. We found that variations in premotor activity were significantly correlated with variations in the acoustic features (pitch, amplitude, and spectral entropy) of syllables in roughly a quarter of all cases. In these cases, individual neural recordings predicted 8.5 +/− 0.3% (mean +/− S.E.) of the behavioral variation, and in some cases accounted for 25% or more of trial-by-trial variations in acoustic output. The prevalence and strength of neuron-behavior correlations indicate that each acoustic feature is controlled by a large ensemble of neurons that vary their activity in a coordinated fashion. Additionally, we found that correlations with pitch (but not other features) were predominantly positive in sign, supporting a model of pitch production based on the anatomy and physiology of the vocal motor apparatus. Collectively, our results indicate that trial-by-trial variations in spectral structure are indeed under central neural control at the level of RA, consistent with the idea that such variation reflects motor exploration.