Mello Claudio V, Velho Tarciso A F, Pinaud Raphael
Laboratory of Vocal and Auditory Learning, Neurological Sciences Institute, Oregon Health & Science University, 505 NW 185th Avenue, West Campus, Bldg. 1, Beaverton, OR 97006, USA.
Ann N Y Acad Sci. 2004 Jun;1016:263-81. doi: 10.1196/annals.1298.021.
We review here evidence that a large portion of the caudomedial telencephalon of songbirds, distinct from the song control circuit, is involved in the perceptual processing of birdsong. When songbirds hear song, a number of caudomedial pallial areas are activated, as revealed by expression of the activity-dependent gene zenk. These areas, which include field L subfields L1 and L3, as well as the adjacent caudomedial nidopallium (NCM) and caudomedial mesopallium (CMM), are part of the central auditory pathway and constitute a lobule in the caudomedial aspect of the telencephalon. Several lines of evidence indicate that the neural circuits integrating this lobule are capable of performing the auditory processing of song based on fine acoustic features. Thus, this lobule is well positioned to mediate song perceptual processing and discrimination, which are required for vocal communication and vocal learning. Importantly, the zenk gene encodes a transcription factor linked to synaptic plasticity, and it regulates the expression of target genes associated with specific neuronal cell functions. The induction of zenk likely represents a key regulatory event in a gene cascade triggered by song and leading to neuronal plasticity. Thus, zenk may be linked to molecular and cellular mechanisms underlying experience-dependent modification of song-responsive circuits. In summary, songbirds possess an elaborate system for song perceptual processing and discrimination that potentially also subserves song-induced neuronal plasticity and song memory formation. The continued use of a multidisciplinary approach that integrates molecular, anatomical, physiological and behavioral methodologies has the potential to provide further significant insights into the underlying neurobiology of the perceptual aspects of vocal communication and learning.
我们在此回顾相关证据，即鸣禽大脑尾内侧端脑的很大一部分，与鸣叫控制回路不同，参与了鸟鸣的感知处理。当鸣禽听到歌声时，一些尾内侧 pallial 区域会被激活，这通过活性依赖基因 zenk 的表达得以揭示。这些区域包括 L 区的 L1 和 L3 亚区，以及相邻的尾内侧巢皮质（NCM）和尾内侧中皮质（CMM），它们是中枢听觉通路的一部分，在端脑的尾内侧形成一个小叶。多条证据表明，整合这个小叶的神经回路能够基于精细的声学特征对歌声进行听觉处理。因此，这个小叶处于很好的位置来介导歌声的感知处理和辨别，而这对于发声交流和发声学习是必需的。重要的是，zenk 基因编码一种与突触可塑性相关的转录因子，它调节与特定神经元细胞功能相关的靶基因的表达。zenk 的诱导可能代表了由歌声触发并导致神经元可塑性的基因级联反应中的一个关键调节事件。因此，zenk 可能与歌声反应回路的经验依赖性修饰所基于的分子和细胞机制有关。总之，鸣禽拥有一个用于歌声感知处理和辨别的精细系统，该系统可能也有助于歌声诱导的神经元可塑性和歌声记忆形成。持续使用整合分子、解剖、生理和行为方法学的多学科方法，有可能为发声交流和学习的感知方面的潜在神经生物学提供进一步的重要见解。
