Imaging Dynamics in Anxiogenic Serotonin Circuitry

项目总结 长期以来，5-羟色胺一直被认为是情绪和行为的重要调节器，但它投射- 人们对具体的动态知之甚少。虽然5-羟色胺在缓解焦虑的环境中已经得到了很好的研究，但它的活性 某些5-羟色胺的投射会增加应激行为。具体地说，来自于 中缝背侧至终纹前背侧床核已被证明是引起焦虑的。尽管 几十年来以5-羟色胺为靶点，对5-羟色胺的功能和释放动力学缺乏共识。 药理学方法、微透析和化学发生操作已经产生了关键的见解，但 它们都不能提供5-羟色胺释放的毫秒分辨率以及特定反应和行为的相关性 直到最近。田实验室正在开发两种针对5-羟色胺的生物传感器(轻微和 ISeroSnFR)，为5-羟色胺研究的新可能性打开了大门。我会把这些传感器和 光学测量焦虑性5-羟色胺回路中行为驱动的5-羟色胺释放的纤维光度法 具有高的时间和空间分辨率。 这项提案中概述的一系列实验意义重大，因为它们将：严格地 展示了5-羟色胺传感器在解剖焦虑回路中的体内效用，为最终用户提供了重要的 快速技术实施的协议和指南。AIM2)5-羟色胺释放的图谱动力学 引起焦虑的回路，应激行为，并发现这一回路的活动如何在焦虑的动物中受到影响 并确定急性和慢性SSRI给药对焦虑性5-羟色胺的机制影响 信号传递；目的3)确定青春期睾酮对焦虑症成熟的发育影响 5-羟色胺活性和SSRI疗效。

PROJECT SUMMARY Serotonin has been long been recognized as an important modulator of mood and behavior, yet it projection- specific dynamics are little understood. While serotonin has been well studied in anxiolytic contexts, activity of certain serotonin projections works to increase stress behaviors. In particular, serotonergic projections from dorsal raphe to the anterodorsal bed nucleus of the stria terminalis have been shown to be anxiogenic. Despite decades of targeting serotonin, a consensus on serotonin function and release dynamic is lacking. Pharmacological approaches, microdialysis, and chemogenetic manipulations have produced key insights, but none provide millisecond resolution for serotonin release and correlates of specific reactions and behaviors until recently. The Tian lab is in the final stages of developing two serotonin specific biosensors (sLight and iSeroSnFR) that open the door for new possibilities in serotonin research. I will these sensors combined with fiber-photometry to optically measure behaviorally driven serotonin release in an anxiogenic serotonin circuit with high temporal and spatial resolution. The series of experiments outlined in this proposal are significant because they will: Aim 1) rigorously demonstrate the in vivo utility of serotonin sensors in dissecting anxiety circuit, providing end users important protocols and guidelines for fast technological implementation; Aim2) map dynamics of serotonin release in anxiogenic circuits to stress behavior, and discover how activity in this circuit is impacted in anxious animals and determine the mechanistic impacts of acute vs. chronic SSRI administration on anxiogenic serotonin signaling; Aim 3) determine the developmental effects of pubertal testosterone on the maturation of anxiogenic serotonin activity and SSRI efficacy.