Establishing the role of dopamine in Vocal Learning in Songbirds

项目总结： 在行为过程中，大脑不断受到感觉反馈的轰炸。学习制作一个合适的 整合感觉信息并进行处理时的运动反应对于任何 有机体。这种感觉运动学习总是依赖于强化提示，无论这些提示是 通过外部或通过对有机体的感觉反馈的内部评估来提供。虽然最近的研究表明， 包括我们自己的工作，都暗示了多巴胺在强化学习中的作用，多巴胺是如何传递的 关于自然行为中的外部增强剂的信息仍然不清楚。 拟议的项目将研究孟加拉人自然行为中基于强化提示的学习。 是雀类。孟加拉雀执行一种刻板印象的习得运动行为(歌曲)，这种行为严重依赖于 用于维护的感官反馈。他们的歌曲由一系列快速发声的手势组成 “音节”)。虽然他们的歌曲在成年后通常是稳定的，但我们的实验室已经开发出一种增强型 学习范例，驱使成年鸟类改变其歌声的一个特殊声学特征(音调)。因此， 我们的建议将使用这一学习范式来阐明多巴胺在联系外部 带有行为的特定组件的强化提示，然后该组件被更改。 我们的中心假设是，多巴胺在强化中执行两个主要的不同计算 学习和这些计算是由两个广泛的多巴胺受体亚型调制。我们会 通过两个具体目标来检验我们的假设。我们的首要目标是使用贝叶斯推理来阐明这些 强化学习的基础计算，并确定每个计算的相对贡献 在学习成功的鸟类身上。我们的第二个目标是使用药物操作来确定 强化学习中的个体多巴胺受体通路。总而言之，我们的研究将大大提高 我们对强化学习背后的神经计算的理解。这样的理解将 此外，有助于识别和最终治疗创伤性脑损伤后发生的学习障碍 伤害或其他神经侮辱。

Project Summary: During behavior, the brain is constantly bombarded with sensory feedback. Learning to produce an appropriate motor response upon integrating that sensory information and processing it is essential for the survival of any organism. Such sensorimotor learning is always dependent on reinforcement cues, whether those cues are provided externally or through an internal evaluation of an organism's sensory feedback. While recent studies, including our own work, have implicated a role for dopamine in reinforcement learning, how dopamine conveys information about an external reinforcer in a naturally occurring behavior is still unclear. The proposed project will study reinforcement cue based learning in a natural behavior in Bengalese finches. Bengalese finches perform a stereotypical learned motor behavior (song) that is heavily dependent on sensory feedback for maintenance. Their song consists of a series of rapidly produced vocal gestures (“syllables”). Though their songs are usually stable in adulthood, our lab has developed a reinforcement learning paradigm that drives adult birds to change one particular acoustic feature of their song (pitch). Thus our proposal will use this learning paradigm to elucidate the role of dopamine in associating an external reinforcement cue with a particular component of behavior that is then changed. Our central hypothesis is that dopamine performs two major distinct computations in reinforcement learning and that these computations are modulated by the two broad subtypes of dopamine receptors. We will test our hypothesis through two specific aims. Our first aim uses Bayesian Inference to elucidate these computations underlying reinforcement learning and identify the relative contributions each computation makes in birds that learned successfully. Our second aim uses pharmacological manipulations to establish the role of individual dopamine receptor pathways in reinforcement learning. To conclude, our studies will greatly enhance our understanding of the neural computations underlying reinforcement learning. Such understanding would furthermore help in identifying and eventually treating learning deficits that occur following traumatic brain injury or other neurological insults.