Social experience: effects on auditory filtering through a serotonergic mechanism

除了众所周知的调节情绪和食欲的作用外，化学物质血清素在大脑对社会互动的反应中起着重要作用。尽管如此，人们对它在一种重要的社会行为--沟通中的作用知之甚少。在他们过去的工作中，研究人员已经表明，血清素改变了老鼠对交流呼叫的听觉反应，而社会伙伴触发了听觉系统中血清素的增加。在大脑的其他区域，多巴胺能系统本身受到过去社会经验的严重影响。有了这个理论基础，研究人员假设社会经验改变了听觉系统在听觉处理中的作用。他们将通过测量单独或社会群体中的小鼠如何影响听觉系统与听觉系统相互作用的方式来测试这一想法。这项工作将探索沟通的基本过程：感觉系统如何适应社会历史等社会环境的特征，并对动物如何对其社会伙伴做出反应产生影响。这项工作也将成为当地K-12外展计划的跳板，在该计划中，本科生将提供关于沟通和感觉系统主题的互动课程。社会经验假设将在雄性和雌性小鼠中进行测试，这些小鼠是越来越多的声音沟通模型。与其他脊椎动物相比，小鼠在听觉区域也表现出高度保守的多巴胺能功能。拟议的工作的具体目标是检查组与个人住房的影响，在下丘（IC），哺乳动物的听觉中脑核的三个功能的阿托宁听觉相互作用。1)其中第一个是IC内的多巴胺能系统的解剖。这将通过测量化学标记的多巴胺能纤维的密度来实现。2)第二个特征是对社会交往的短暂性多巴胺能反应。这将使用碳纤维伏安法在行为动物的IC中进行局部测量。3)最后一个特征是通过社会相互作用对c-fos转录途径的激活的β-羟色胺能调节，这将通过诱导全身性5-羟色胺释放或耗尽来探索。这些研究将提供一个框架，社会经验如何在组织的多个层次上创造可塑性的神经肽-5-羟色胺相互作用，产生可检验的假设，这种可塑性的神经编码和感知的下游后果。

In addition to its well-known roles in regulating mood and appetite, the chemical serotonin plays an important role in the response of the brain to social interaction. Despite this, very little is known about its role in a crucial type of social behavior, communication. In their past work, the researchers have shown that serotonin modifies auditory responses to communication calls in mice, and that social partners trigger these increases in serotonin in the auditory system. In other regions of the brain, the serotonergic system itself is heavily influenced by past social experience. With this rationale, the researchers hypothesize that social experience changes the role of the serotonergic system in auditory processing. They will test this idea by measuring how housing mice individually or in social groups affects the way that the serotonergic system interacts with the auditory system. This work will explore a process fundamental to communication: how sensory systems adapt to features of the social environment like social history, with implications for how animals respond to their social partners. The work will also serve as a springboard for a local K-12 outreach program in which undergraduates present interactive lessons on themes of communication and sensory systems.The social experience hypothesis will be tested in male and female mice, which are increasingly studied models of vocal communication. Mice also demonstrate highly conserved serotonergic function in auditory regions compared with other vertebrates. The specific objectives of the proposed work are to examine the effect of group versus individual housing on three features of serotonin-auditory interactions in the inferior colliculus (IC), a mammalian auditory midbrain nucleus. 1) The first of these is the anatomy of the serotonergic system within the IC. This will be accomplished by measuring the density of immunohistochemically labeled serotonergic fibers. 2) A second feature is the transient serotonergic response to social interactions. This will be measured locally in the IC of behaving animals using carbon fiber voltammetry. 3) A final feature is the serotonergic regulation of the activation of the c-fos transcriptional pathway by social interaction, which will be explored by inducing systemic release or depletion of serotonin. These studies will provide a framework of how social experience creates plasticity in auditory-serotonin interactions at multiple levels of organization, generating testable hypotheses on the downstream consequences of such plasticity for neural encoding and perception.