Baran Nicole M, Peck Samantha C, Kim Tabitha H, Goldstein Michael H, Adkins-Regan Elizabeth
Department of Psychology, Cornell University, Ithaca, NY 14853, USA
School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Proc Biol Sci. 2017 Jul 26;284(1859). doi: 10.1098/rspb.2017.1114.
Vocal learning from social partners is crucial for the successful development of communication in a wide range of species. Social interactions organize attention and enhance motivation to learn species-typical behaviour. However, the neurobiological mechanisms connecting social motivation and vocal learning are unknown. Using zebra finches (), a ubiquitous model for vocal learning, we show that manipulations of nonapeptide hormones in the vasopressin family (arginine vasotocin, AVT) early in development can promote or disrupt both song and social motivation. Young male zebra finches, like human infants, are socially gregarious and require interactive feedback from adult tutors to learn mature vocal forms. To investigate the role of social motivational mechanisms in song learning, in two studies, we injected hatchling males with AVT or Manning compound (MC, a nonapeptide receptor antagonist) on days 2-8 post-hatching and recorded song at maturity. In both studies, MC males produced a worse match to tutor song than controls. In study 2, which experimentally controlled for tutor and genetic factors, AVT males also learned song significantly better compared with controls. Furthermore, song similarity correlated with several measures of social motivation throughout development. These findings provide the first evidence that nonapeptides are critical to the development of vocal learning.
从社会伙伴那里进行声音学习对于众多物种成功发展交流能力至关重要。社会互动能够组织注意力并增强学习物种典型行为的动机。然而，连接社会动机和声音学习的神经生物学机制尚不清楚。利用斑胸草雀（一种广泛应用于声音学习研究的模型），我们发现，在发育早期对血管加压素家族中的九肽激素（精氨酸血管催产素，AVT）进行操控，能够促进或扰乱鸣叫以及社会动机。幼年雄性斑胸草雀和人类婴儿一样，具有社会群居性，需要成年“导师”的互动反馈来学习成熟的发声形式。为了研究社会动机机制在鸣叫学习中的作用，在两项研究中，我们在孵化后第2至8天给刚孵化出的雄性斑胸草雀注射AVT或曼宁化合物（MC，一种九肽受体拮抗剂），并在其成熟时记录其鸣叫。在两项研究中，注射MC的雄性斑胸草雀发出的鸣叫与“导师”鸣叫的匹配度都比对照组差。在研究2中，该研究对“导师”和遗传因素进行了实验控制，注射AVT的雄性斑胸草雀与对照组相比，学习鸣叫的能力也显著更强。此外，在整个发育过程中，鸣叫相似度与社会动机的多项指标相关。这些发现首次证明九肽对于声音学习的发展至关重要。
