Mechanisms for internally and externally guided sensorimotor learning

项目摘要 表达性的社会行为，包括演讲和音乐，是从文化上从导师传递给学生的。 这种学习依赖于学生的能力，整合社会和感官线索提供的导师表演 相关行为。一旦学会了，潜在的运动程序必须与一系列先天的 运动程序，以产生有效的社会信号所必需的整体行为。核心假设 这项建议试图测试的是，使学生能够整合社会和 来自成人导师的感觉线索在成人中也起作用，使习得和先天的能力得以整合。 有效的社会信号所必需的程序。在过去的周期中，我们发现神经信号 由导师提供的社会和感官线索的编码被整合到学生的大脑中。我们特别 表明幼年鸣禽中脑多巴胺细胞群（A11）中的神经元选择性兴奋， 在与唱歌的成年男性导师的互动中，将歌曲播放与光遗传学配对， 在感觉运动皮质类似物（HVC）中，从A11末端触发释放多巴胺足以 驱动歌曲复制。尽管有这些重要的见解，导师体验到底何时以及如何转变 听觉和运动编码在HVC促进声乐学习仍然是未知的。因此，在目标1中， 采用多光子（2 p）纵向成像、光纤光度法检验导师经验快速的假设 增强了小学生HVC的听觉和运动网络。我们还将使用新颖的机器学习工具 声音分析和光遗传学方法来测试这些感觉运动变化使HVC能够 增强学生歌声的声学复杂性，这是模仿声音的第一步。我们先前的研究支持 导师提供的社会和听觉线索驱动DA释放和听觉突触同步的想法 活动在瞳孔的HVC，迅速增强感觉运动突触在这一地区。在目标2中，我们 将使用离体通道视紫红质电路映射来测试同时DA释放和 听觉突触活动迅速加强听觉突触到HVC中间神经元，这些作用 在青少年学习敏感期最强。值得注意的是，成年鸣禽的求偶表演 包括一首习得的歌曲，它与各种天生的行为无缝协调，包括女性- 定向呼叫定向和追踪在初步研究中，我们发现A11轴突终末的损伤 在HVC的成年雄性雀废除女性指导的歌声，而不影响他天生的求爱 行为。相比之下，选择性地切除A11细胞体消除了所有男性的求偶行为。在 目标3，我们将绘制、监测和操纵A11到HVC和其他运动中枢的投射，以验证这一想法 A11作为一个中心枢纽，使学习和先天运动的无缝和快速的协调， 根据附近的女性提供的社交线索进行编程。

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.