Mechanisms of context: modulatory feedback to the auditory system

对于大多数群居动物来说，声音交流在很大程度上受到其发生的环境的影响。动物发出的叫声，以及它们对其他动物发出的叫声做出反应的方式，取决于个体直接的社会环境。这一系列研究将探索神经调节剂血清素在大脑听觉区域发出环境信号的能力，从而使听觉系统以与环境相适应的方式对呼叫做出反应。听觉神经元血清素的作用将在实验室小鼠中得到解决，这些小鼠产生丰富的上下文依赖呼叫曲目。这些研究将解决1)5 -羟色胺如何反映大脑听觉区域内社会环境的不同特征，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环境依赖性呼叫的行为反应。由于将被研究的大脑听觉区域和该区域血清素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”。本计画的目标是让学生对老鼠声音信号的功能提出假设，并透过精选的音视频档案进行测试。对于大多数群居动物来说，产生和回应交流发声在很大程度上依赖于社会环境。越来越多的证据表明，感觉系统对社会环境很敏感，但社会大脑区域如何与感觉系统合作来表示环境信息还没有得到很好的理解。这些研究将检验一个模型，即高级社会区域在一定程度上通过血清素能系统对社会背景下的听觉系统进行指导。该研究将在实验室小鼠中完成，这些小鼠具有丰富的上下文依赖的声音信号和反应，这些信号和反应受急性事件、先前经验和内部状态的影响。实验将集中于下丘（IC），这是一个保守的听觉瓶颈，对许多声音驱动的行为很重要。三个主要目标将解决1)5 -羟色胺如何反映大脑听觉区域内社会环境的不同特征，2)5 -羟色胺如何改变听觉神经元对发声的反应，3)5 -羟色胺的变化如何影响小鼠对环境依赖性呼叫的行为反应。这些目标将依赖于最近发展的一种行为范式，即雄性老鼠对雌性吱吱声的反应是抑制求爱的声音。这些研究将为社会脑区如何指导感觉系统提供新的信息，并进一步关注感觉脑区在社会决策中的作用。与这些研究相关的一个拓展项目将利用精心策划的老鼠社交互动的音频和视频文件，培养初中生和高中生的假设测试技能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.