Interdepartmental Program in Molecular, Cellular and Integrative Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
J Exp Biol. 2013 Oct 1;216(Pt 19):3682-92. doi: 10.1242/jeb.085886.
Humans and songbirds are among the rare animal groups that exhibit socially learned vocalizations: speech and song, respectively. These vocal-learning capacities share a reliance on audition and cortico-basal ganglia circuitry, as well as neurogenetic mechanisms. Notably, the transcription factors Forkhead box proteins 1 and 2 (FoxP1, FoxP2) exhibit similar expression patterns in the cortex and basal ganglia of humans and the zebra finch species of songbird, among other brain regions. Mutations in either gene are associated with language disorders in humans. Experimental knock-down of FoxP2 in the basal ganglia song control region Area X during song development leads to imprecise copying of tutor songs. Moreover, FoxP2 levels decrease naturally within Area X when zebra finches sing. Here, we examined neural expression patterns of FoxP1 and FoxP2 mRNA in adult Bengalese finches, a songbird species whose songs exhibit greater sequence complexity and increased reliance on audition for maintaining their quality. We found that FoxP1 and FoxP2 expression in Bengalese finches is similar to that in zebra finches, including strong mRNA signals for both factors in multiple song control nuclei and enhancement of FoxP1 in these regions relative to surrounding brain tissue. As with zebra finches, when Bengalese finches sing, FoxP2 is behaviorally downregulated within basal ganglia Area X over a similar time course, and expression negatively correlates with the amount of singing. This study confirms that in multiple songbird species, FoxP1 expression highlights song control regions, and regulation of FoxP2 is associated with motor control of song.
分别为言语和歌声。这些发声学习能力都依赖于听觉和皮质基底神经节回路以及神经遗传机制。值得注意的是，转录因子叉头框蛋白 1 和 2（FoxP1、FoxP2）在人类和鸣禽的斑马雀物种的大脑皮质和基底神经节中表现出相似的表达模式，以及其他脑区。这两个基因的突变都与人类的语言障碍有关。在鸣禽歌曲控制区 X 的基底神经节发育过程中，实验性敲低 FoxP2 会导致导师歌曲的复制不准确。此外，当斑马雀唱歌时，FoxP2 水平在 X 区自然下降。在这里，我们检查了 FoxP1 和 FoxP2 mRNA 在成年孟加拉雀中的神经表达模式，孟加拉雀是一种鸣禽，其歌曲表现出更高的序列复杂性，并增加了对听觉的依赖来维持其质量。我们发现，FoxP1 和 FoxP2 在孟加拉雀中的表达与斑马雀相似，包括这两个因素在多个歌曲控制核中的强烈 mRNA 信号，以及相对于周围脑组织 FoxP1 在这些区域的增强。与斑马雀一样，当孟加拉雀唱歌时，FoxP2 在类似的时间过程中在基底神经节的 X 区中表现出行为下调，表达与唱歌量呈负相关。这项研究证实，在多种鸣禽物种中，FoxP1 的表达突出了歌曲控制区域，而 FoxP2 的调节与歌曲的运动控制有关。
