Laboratory of Animal Behavior, The Rockefeller University, New York, New York, 10065, USA.
Nat Commun. 2013;4:2082. doi: 10.1038/ncomms3082.
Vocal learning has evolved in only a few groups of mammals and birds. The key neuroanatomical and behavioural links bridging vocal learners and non-learners are still unknown. Here we show that a non-vocal-learning suboscine, the eastern phoebe, expresses neural and behavioural substrates that are associated with vocal learning in closely related oscine songbirds. In phoebes, a specialized forebrain region in the intermediate arcopallium seems homologous to the oscine song nucleus RA (robust nucleus of arcopallium) by its neural connections, expression of glutamate receptors and singing-dependent immediate-early gene expression. Lesion of this RA-like region induces subtle but consistent song changes. Moreover, the unlearned phoebe song unexpectedly develops through a protracted ontogeny. These features provide the first evidence of forebrain vocal-motor control in suboscines, which has not been encountered in other avian non-vocal-learners, and offer a potential configuration of brain and behaviour from which vocal learning might have evolved.
鸣叫学习仅在少数几种哺乳动物和鸟类中进化而来。连接鸣叫学习者和非学习者的关键神经解剖学和行为联系仍不清楚。在这里，我们表明，一种非鸣叫学习的 suboscine，东方翠鸟，表达了与相关鸣禽鸣叫声学习相关的神经和行为基质。在翠鸟中，中脑弓状皮层中的一个专门的前脑区域通过其神经连接、谷氨酸受体的表达和与歌唱相关的即时早期基因表达，似乎与鸣禽 song 核 RA（弓状核）同源。该 RA 样区域的损伤会导致细微但一致的歌声变化。此外，未被学习的翠鸟歌声出人意料地通过延长的个体发育发展而来。这些特征首次提供了鸣禽中前脑发声运动控制的证据，这在其他非鸣禽学习者中尚未遇到，并且提供了一种潜在的大脑和行为配置，鸣叫学习可能从中进化而来。
