Roles of nuleus accumbens CREB and Kappa function in depression

总结 本申请是为了竞争性地更新一项赠款，该赠款在其20年的课程中阐明了 核内转录因子CREB和κ-阿片受体（KOR）系统的功能 神经元（NAc）会因经历而改变，包括压力暴露，以及它们的功能如何改变 影响行为我们已经证明，（a）应激上调NAc、CREB和KOR信号，（B）这些效应 足以产生情绪和焦虑障碍的特征性特征，以及（c）CREB的破坏或 KOR的阻断产生抗抑郁和抗焦虑样作用。最近，我们还显示了一个作用， 这些系统在睡眠和生物（昼夜）节律，这是失调，在许多类型的精神疾病 病我们的工作为KOR拮抗剂治疗抑郁症的临床试验提供了基础， 大有希望。21-25年级的主要目标是进一步描述NAc CREB和 KOR系统调节复杂的行为和对不同形式的压力源的反应，包括一种类型的压力。 与COVID-19大流行相关的免疫应激，同时优先考虑使用啮齿类动物的终点， 与人类使用的药物更好的匹配。在目标1中，我们将研究CREB介导的 使用我们开发的认知控制任务（称为Flanker任务）的新版本来研究抑郁行为 使老鼠和人类的测试能够使用几乎相同的程序。具体来说，我们将确定如何 在D1和/或D2中棘神经元（MSN）中NAc CREB功能的改变影响任务表现， 事件相关电位（ERP）-已知在人类抑郁症中异常的终点-男性和女性 大鼠在目标2中，我们将确定早期免疫激活（EIA）方案是否能产生持久的免疫应答。 在小鼠中的抑郁样作用引起NAc CREB和KOR系统的持续改变。我们特别 将使用单核RNA测序来全面检查EIA诱导的NAc细胞中的改变， 人群，包括MSN和小胶质细胞，并比较和对比男性和女性的影响。而 目的3-4中，NAc CREB和KOR系统的上调通常与抑郁表型相关 我们将探讨压力复原力的可能作用。对于目标3，我们将研究KOR如何在 调节免疫功能的小胶质细胞影响对压力的敏感性。具体来说，我们将研究如何消融 来自小胶质细胞的KOR影响慢性应激破坏睡眠和昼夜活动节律的能力， 体温同样，在目标4中，我们将描述改变CREB靶点功能的影响 D1-或D2-MSN中的DFosB对应激诱导的睡眠和昼夜节律中断的影响，同时平行检查 对NAc MSNs和小胶质细胞中CREB、DYN和KOR表达的影响。所有这些研究都涉及终点 （行为的，分子的），也可以在人类或人类组织中进行研究。这项工作将提高我们的 了解NAc CREB和KOR功能影响经常被 研究人员发现，这种方法可能会导致情绪和焦虑症的失调，并可能使诊断和治疗这些疾病的新方法成为可能。

SUMMARY This application is for competitive renewal of a grant that over its 20-year course has elucidated the ways in which the function of the transcription factor CREB and kappa-opioid receptor (KOR) systems within the nucleus accumbens (NAc) are changed by experience, including stress exposure, and how alterations in their function affect behavior. We have shown that (a) stress upregulates NAc CREB and KOR signaling, (b) these effects are sufficient to produce characteristic features of mood and anxiety disorders, and (c) disruption of CREB or blockade of KORs produces antidepressant- and anxiolytic-like effects. Recently we have also shown a role for these systems in sleep and biological (diurnal) rhythms, which are dysregulated across many types of psychiatric illness. Our work has provided a basis for clinical trials of KOR antagonists to treat depression, which thus far show great promise. Major goals for Years 21-25 are to further characterize the ways in which NAc CREB and KOR systems regulate complex behavior and responses to different forms of stressors, including a type of immune stress relevant to the COVID-19 pandemic, while prioritizing the use of endpoints in rodents with improved alignment to those used in humans. In Aim 1, we will examine the mechanisms of CREB-mediated depressive behavior using a new version of a cognitive control task (called the Flanker task) that we developed to enable testing rats and humans using virtually identical procedures. Specifically, we will determine how alterations in NAc CREB function in D1- and/or D2-medium spiny neurons (MSNs) affect task performance and event-related potentials (ERPs)—endpoints known to be aberrant in human depression—in male and female rats. In Aim 2, we will determine if a regimen of early immune activation (EIA) that produces long-lasting depressive-like effects in mice causes persistent alterations in NAc CREB and KOR systems. Specifically, we will use single-nucleus RNA sequencing to comprehensively examine EIA-induced alterations in NAc cell populations, including MSNs and microglia, and compare and contrast effects in males and females. While upregulation of NAc CREB and KOR systems is commonly associated with depressive phenotypes, in Aims 3-4 we will examine possible roles in stress resilience. For Aim 3, we will examine how KORs expressed on microglia, which regulate immune function, affect sensitivity to stress. Specifically, we will examine how ablation of KORs from microglia affects the ability of chronic stress to disrupt sleep and diurnal rhythms of activity and body temperature. Similarly, in Aim 4 we will characterize the effects of altering the function of the CREB target DFosB in D1- or D2-MSNs on stress-induced disruption of sleep and diurnal rhythms, while in parallel examining effects on CREB, DYN, and KOR expression in NAc MSNs and microglia. All of these studies involve endpoints (behavioral, molecular) that can also be studied in humans or human tissues. This work will improve our understanding of the mechanisms by which NAc CREB and KOR function affect domains that are frequently dysregulated in mood and anxiety disorders, and may enable new ways to diagnose and treat these conditions.