Neural Bases of Song Preference and Reproductive Behavior in a Female Songbird

几十年来，神经科学家和进化生物学家一直对鸣禽“鸣叫系统”的机制和功能感兴趣：连接大脑中高级听觉区域和脑干中驱动行为的运动回路的相互连接的神经回路。这项工作主要集中在鸣叫系统如何使雄性鸣禽学习和鸣叫。这个回路在不唱歌的雌性鸣禽中的作用在很大程度上被忽视了。这项研究不是作为一个产生发声行为的回路，而是调查了一个假设，即雌性的“鸣叫系统”是用来组织对雄性鸣叫的偏好，并以一种求偶展示的形式指导它们对鸣叫的行为反应，以确保物种的生存。该项目利用棕头牛鹂交配行为的稳健性、选择性和社会可塑性，研究鸣叫系统如何将感觉刺激（鸣叫）转化为控制姿势反应的运动命令。该项目还为本科生和研究生提供了参与跨学科研究的机会，它包括针对小学生的科学教育活动以及针对高中生的神经科学综合暑期课程。这项工作整合了不同的科学领域，包括神经科学、行为学和工程学，为控制行为的神经回路的进化提供了独特的见解。在第一个目标中，研究人员结合了经典的途径追踪技术和最近开发的跨突触示踪剂（水疱性口炎病毒）来绘制从前脑到个体肌肉群的连通性，这些肌肉群在交配请求显示（CSD）的产生过程中被激活。在第二个目标中，研究人员记录了雌性牛鹂在产生CSD过程中前脑鸣叫控制核HVC和RA的神经活动，以量化控制这种高度选择性性行为的前脑运动命令的性质。为了评估记录的神经活动模式与行为之间的关系，我们将使用计算机视觉方法来量化交配行为。在该提案的最终目的中，研究人员记录了在CSD产生的背景下，高阶听觉前脑区域（NCM, NIf， CM）对歌曲的神经反应。这些实验是为了验证这样的假设，即这些前脑区域，已知对鸣叫控制核的投射，编码鸣叫的价，并在鸣叫质量和雌性行为反应之间提供直接联系。神经和行为数据将在专门研究鸣禽科学的公共网站上公布。

For many decades, neuroscientists and evolutionary biologists have been interested in the mechanics and function of the songbird's "song system": the interconnected neural circuit that connects the higher-order auditory areas in the brain with the motor circuits in the brainstem that drive behavior. This work predominantly has focused on how the song system allows male songbirds to learn and produce song. The role of this circuit in female songbirds, which do not sing, has largely been ignored. Rather than acting as a circuit that generates vocal behavior, this work investigates the hypothesis that the "song system" in females serves to organize preferences for males' songs and guides their behavioral reactions to song in the form of a copulation solicitation display that ensures survival of the species. The project capitalize on the robustness, selectivity, and social malleability of the copulatory behavior in the brown-headed cowbird, to investigate how the song system transforms a sensory stimulus (the song) into a motor command that controls a postural response. The project also provides opportunities for undergraduate and graduate students to engage in interdisciplinary research, and it includes science education activities aimed at elementary school children as well as a comprehensive summer course in neuroscience for high school students.The proposed work integrates disparate fields of science, including neuroscience, behavior, and engineering to provide unique insight into the evolution of neural circuits that control behavior. In the first aim, the investigators use a combination of classic pathway tracing techniques and recently developed transsynaptic tracer (vesicular stomatitis virus) to map the connectivity from the forebrain to the individual muscle groups that are activated during the production of a copulation solicitation display (CSD). In the second aim, the investigators record neural activity in forebrain song control nuclei HVC and RA during the production of CSD in female cowbirds to quantify the nature of the forebrain motor commands that control this highly selective sexual behavior. To evaluate the relationship between recorded neural activity patterns and the behavior, we will use a computer vision approach to quantify the copulatory behavior. In the final aim of the proposal, the investigators record neural responses to song in higher-order auditory forebrain areas (NCM, NIf, CM) within the context of CSD production. These experiments serve to test the hypothesis that these forebrain areas, which have known projections to song control nuclei, encode song valence and provide a direct link between song quality and the females' behavioral response. The neural and behavioral data will be made available at public internet site dedicated to Song Bird Science.