Mechanisms of context: modulatory feedback to the auditory system

对于大多数群居动物来说，声音交流很大程度上受到其发生的语境的影响。动物发出的叫声，以及它们对其他动物发出的叫声的回应方式，都取决于一个人所处的直接社会环境。这组研究将探索神经调节剂5-羟色胺在听觉脑区内发出背景信号的能力，使听觉系统能够以与背景相适应的方式对呼叫做出反应。听觉神经元5-羟色胺的作用将在实验室小鼠中得到解决，这将产生丰富的上下文相关呼叫曲目。这些研究将涉及1)5-羟色胺如何在大脑的听觉区域反映社会背景的不同特征，2)5-羟色胺如何改变听觉神经元对呼叫的反应，以及3)5-羟色胺的变化如何影响小鼠对上下文相关呼叫的行为反应。由于将要研究的听觉大脑区域以及该区域中5-羟色胺的存在在一系列脊椎动物物种中都是保守的，这些研究将阐明大脑如何使用有关环境的信息的基本原理。这些研究还将强调感官系统在社会决策中发挥的积极作用。与这些研究相结合，该奖项将支持为K-12学生开发一个在线教育单元：《解码老鼠的秘密语言》。这个项目的目标是让学生开发关于鼠标发声信号功能的假设，并通过精选的音频和视频文件对其进行测试。对于大多数群居动物来说，交流发声的产生和反应在很大程度上依赖于社会背景。越来越多的证据表明，感觉系统对社会背景很敏感，但社会大脑区域如何与感觉系统合作来代表背景信息还没有被很好地理解。这些研究将检验这样的模型，即较高的社会区域部分通过5-羟色胺能系统指导听觉系统对社会背景的反应。这些研究将在实验室小鼠身上完成，小鼠拥有丰富的上下文相关声音信号和反应曲目，这些信号和反应受到急性事件、先前经验和内部状态的影响。实验将重点放在下丘(IC)上，这是一种保守的听觉瓶颈，对许多听觉驱动行为很重要。三个主要目标将涉及1)5-羟色胺如何在大脑的听觉区域反映社会背景的不同特征，2)5-羟色胺如何改变听觉神经元对发声的反应，以及3)5-羟色胺的变化如何影响小鼠对上下文相关呼叫的行为反应。这些目标将依赖于最近开发的一种行为范式，在该范式中，雄性小鼠通过抑制求偶发声来回应雌性的尖叫。这些研究将提供有关社会大脑区域如何指导感觉系统的新信息，并另外关注感觉大脑区域在社会决策中的作用。与这些研究相关的一个推广项目将在初中生和高中生中使用经过策划的社会互动小鼠的音频和视频文件来培养假设检验技能。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

For most social animals, vocal communication is heavily influenced by the context in which it occurs. The calls that animals produce, as well as the ways they respond to calls produced by others, depend on an individual's immediate social environment. The set of studies will explore the ability of the neuromodulator, serotonin, to signal context within auditory brain regions, allowing the auditory system to respond to calls in context-appropriate ways. The role of auditory neuron serotonin will be addressed in laboratory mice, which produce a rich repertoire of context-dependent calls. The studies will address 1) how serotonin reflects different features of the social context within auditory regions of the brain, 2) how serotonin alters the responses of auditory neurons to calls and 3) how changes in serotonin influence behavioral responses of mice to context-dependent calls. Because the auditory brain region that will be studied and the presence of serotonin in this region are conserved across a range of vertebrate species, these studies will illustrate basic principles of how the brain uses information about context. These studies will also emphasize the active role that sensory systems play in social decision-making. In conjunction with these studies, this award will support the development of an online educational unit for K-12 students: 'Decoding the secret language of mice'. The goal of this project is for students to develop hypotheses on the functions of mouse vocal signals and test them through curated audio and video files. For most social animals, producing and responding to communication vocalizations is heavily dependent on the social context. There is growing evidence that sensory systems are sensitive to social context, but how social brain regions collaborate with sensory systems to represent contextual information is not well understood. The studies will test the model that higher social regions instruct the auditory system on social context in part through the serotonergic system. The studies will be accomplished in laboratory mice, which have a rich repertoire of context-dependent vocal signals and responses that are influenced by acute events, prior experience, and internal state. Experiments will focus on the inferior colliculus (IC), a conserved auditory bottleneck important to a number of acoustically driven behaviors. Three main objectives will address 1) how serotonin reflects different features of the social context within auditory regions of the brain, 2) how serotonin alters the responses of auditory neurons to vocalizations and 3) how changes in serotonin influence behavioral responses of mice to context-dependent calls. These objectives will rely on a recently developed behavioral paradigm in which male mice respond to female squeaks with the suppression of courtship vocalizations. These studies will provide novel information on how social brain regions instruct sensory systems, and additionally focus on the role of sensory brain regions in social decision-making. An outreach project associated with these studies will develop hypothesis-testing skills in junior high- and high school students using curated audio and video files of socially interacting mice.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.