Department of Psychology, Emory University, Atlanta, Georgia, USA.
Dev Neurobiol. 2022 Jan;82(1):3-15. doi: 10.1002/dneu.22851. Epub 2021 Dec 4.
Like human language, song in songbirds is learned during an early sensitive period and is facilitated by motivation to seek out social interactions with vocalizing adults. Songbirds are therefore powerful models with which to understand the neural underpinnings of vocal learning. Social motivation and early social orienting are thought to be mediated by the oxytocin system; however, the developmental trajectory of oxytocin receptors in songbirds, particularly as it relates to song learning, is currently unknown. This gap in knowledge has hindered the development of songbirds as a model of the role of social orienting in vocal learning. In this study, we used quantitative PCR to measure oxytocin receptor expression during the sensitive period of song learning in zebra finches (Taeniopygia guttata). We focused on brain regions important for social motivation, attachment, song recognition, and song learning. We detected expression in these regions in both sexes from posthatch day 5 to adulthood, encompassing the entire period of song learning. In this species, only males sing; we found that in regions implicated in song learning specifically, oxytocin receptor mRNA expression was higher in males than females. These sex differences were largest during the developmental phase when males attend to and memorize tutor song, suggesting a functional role of expression in learning. Our results show that oxytocin receptors are expressed in relevant brain regions during song learning, and thus provide a foundation for developing the zebra finch as a model for understanding the mechanisms underlying the role of social motivation in vocal development.
像人类语言一样，鸣禽的歌声是在早期的敏感时期通过寻求与发声成鸟进行社交互动的动机而习得的。因此，鸣禽是理解发声学习神经基础的有力模型。社会动机和早期社会定向被认为是由催产素系统介导的；然而，目前尚不清楚鸣禽中催产素受体的发育轨迹，特别是与歌曲学习有关的发育轨迹。这方面知识的空白阻碍了鸣禽作为社会定向在发声学习中作用模型的发展。在这项研究中，我们使用定量 PCR 测量了在斑马雀（Taeniopygia guttata）学习歌曲的敏感时期中催产素受体的表达。我们专注于对社会动机、依恋、歌曲识别和歌曲学习很重要的大脑区域。我们在从孵化后第 5 天到成年的两性中检测到了这些区域的表达，涵盖了整个歌曲学习时期。在这个物种中，只有雄性唱歌；我们发现，在与歌曲学习特别相关的区域中，雄性的催产素受体 mRNA 表达高于雌性。在雄性关注和记忆导师歌曲的发育阶段，这些性别差异最大，这表明表达在学习中具有功能作用。我们的研究结果表明，在学习歌曲期间，催产素受体在相关的大脑区域中表达，从而为将斑马雀作为理解社会动机在发声发育中作用的机制的模型提供了基础。
