Mechanisms for internally and externally guided sensorimotor learning

项目总结 富有表现力的社会行为，包括言语和音乐，从文化上从家庭教师传递给学生。 这种学习依赖于小学生整合社会和感官线索的能力，这些线索由导师提供 相关行为。一旦学习，潜在的运动程序必须与一系列与生俱来的 运动程序，以产生有效的社会信号所必需的整体行为。中心假说 这项提议试图测试的是，使学生能够整合社会和 来自成人导师的感官暗示在成人中也起作用，使后天和先天的整合成为可能。 有效的社交信号所必需的程序。在过去的周期中，我们发现神经信号 由导师提供的编码社交和感觉线索整合在学生的大脑中。具体来说，我们 显示幼年鸣禽中脑多巴胺细胞群(A11)的神经元被选择性地兴奋 在与一位会唱歌的成年男性家教的互动中，以及与光遗传学的配对歌曲回放- 从感觉运动皮质类似物(HVC)的所有11个终末触发的多巴胺释放足以 驱动歌曲复制。尽管有这些重要的见解，但辅导经验到底是在什么时候以及如何转变的 HVC中促进发声学习的听觉和运动编码仍不清楚。因此，在目标1中，我们将 使用多光子(2p)纵向成像、光纤光度法来验证导师快速体验的假设 加强学生HVC中的听觉和运动网络。我们还将使用新的机器学习工具 用于声音分析和光遗传学方法，以测试这些感觉运动变化使HVC能够 增强学生歌曲的声学复杂性，这是复制声音的第一步。我们之前的研究支持 认为由导师提供的社会和听觉提示驱动一致的DA释放和听觉突触 小学生HVC的活动，迅速增强该区域的感觉运动性突触。因此，在目标2中，我们 将使用体外通道视紫红质电路映射来测试符合DA释放和 听觉突触的活性迅速增强了与HVC中间神经元的听觉突触，并且这些效应 在青少年学习敏感期是最强的。值得注意的是，成年鸣禽的求偶表演 包括一首习得的歌曲，与各种先天行为无缝协调，包括女性- 定向呼唤、定向和追逐。在初步研究中，我们发现A11‘S轴突终末病变 在成年雄雀的HVC中，取消雌性指导的歌唱，而不影响它天生的求偶行为 行为。相比之下，选择性地消融A11细胞体会消除雄性所有的求偶行为。在……里面 目标3，我们将地图，监测和操作A11‘S投射到下腔静脉和其他运动中心，以验证这一想法 A11作为一个中心枢纽，使后天习得的运动和先天的运动能够无缝而快速地协调 对附近女性提供的社交暗示做出反应的节目。

PROJECT SUMMARY Expressive social behaviors, including speech and music, are culturally transmitted from a tutor to a pupil. Such learning depends on a pupil’s ability to integrate social and sensory cues provided by a tutor performing the relevant behavior. Once learned, the underlying motor program must be coordinated with a range of innate motor programs to generate holistic behaviors necessary to effective social signaling. The central hypothesis that this proposal seeks to test is that the same brain circuitry that enables the pupil to integrate social and sensory cues from an adult tutor also function in the adult to enable integration of the learned and innate programs necessary to effective social signaling. In the past cycle, we discovered where neural signals encoding social and sensory cues provided by a tutor are integrated in the pupil’s brain. Specifically, we showed that neurons in a midbrain dopamine cell group (A11) in a juvenile songbird are selectively excited during interactions with a singing adult male tutor, and that pairing song playback with the optogenetically- triggered release of dopamine from A11 terminals in a sensorimotor cortical analogue (HVC) is sufficient to drive song copying. Despite these important insights, exactly when and how tutor experience transforms auditory and motor coding in HVC to facilitate vocal learning remains unknown. Therefore, in Aim 1 we will use multiphoton (2p) longitudinal imaging, fiber photometry to test the hypothesis that tutor experience rapidly strengthens the auditory and motor network in the pupil’s HVC. We will also use novel machine learning tools for vocal analysis and optogenetic methods to test the idea that these sensorimotor changes enable HVC to enhance the acoustic complexity of the pupil’s song, a first step in vocal copying. Our prior studies support the idea that social and auditory cues provided by the tutor drive coincident DA release and auditory synaptic activity in the pupil’s HVC, rapidly potentiating sensorimotor synapses in this region. Therefore, in Aim 2, we will use ex vivo channelrhodopsin circuit-mapping to test the hypothesis that coincident DA release and auditory synaptic actvity rapidly potentiates auditory synapses onto HVC interneurons, and that these effects are strongest during juvenile sensitive periods for learning. Notably, the courtship display of the adult songbird includes a learned song that is seamlessly coordinated with a variety of innate behaviors, including female- directed calling, orientation, and pursuit. In Preliminary Studies, we found that lesions of A11’s axon terminals in HVC of the adult male finch abolish female-directed singing without affecting his innate courtship behaviors. In contrast, selectively ablating A11 cell bodies abolished all of the male’s courtship behaviors. In Aim 3, we will map, monitor and manipulate A11’s projections to HVC and other motor centers to test the idea that A11 acts as a central hub to enable the seamless and rapid coordination of learned and innate motor programs in response to social cues provided by a nearby female.