Effect of Stress on Glutamate Receptors and Signaling Proteins in the Basolateral

描述(由申请人提供)： 压力是一种调节动物行为和神经系统功能的强大刺激。在人身上，压力对与退伍军人事务部临床任务相关的各种精神疾病产生负面影响，包括抑郁、焦虑和药物滥用。特别是，在军人和平民中，暴露在严重压力下与创伤后应激障碍(PTSD)有关。这些情况对我们的退伍军人来说是一个主要的健康问题，现有的治疗充其量是部分有效的。迫切需要更好地了解压力对大脑功能的影响，以便为与压力相关的疾病设计更好的治疗方法。对人类和动物的研究表明，杏仁核是参与调节对压力的行为反应的大脑区域，创伤后应激障碍患者的这一大脑区域活动增加。尤其是杏仁核的基底外侧复合体(BLA)对杏仁核的正常和病理性功能至关重要。BLA对压力的反应已被证明涉及该脑区内兴奋性谷氨酸能连接的突触可塑性。虽然复杂突触可塑性是一种复杂的现象，但许多研究表明，它涉及谷氨酸受体的NMDA和AMPA亚型，以及信号转导蛋白CaMKII。阻断这些蛋白质活性的操作会阻断对压力的行为反应。有证据表明，这些蛋白质对改变的活动水平和压力的反应涉及改变的定位模式。通过对NMDA和AMPA受体的NR1和GluR1亚单位以及CaMKII的免疫组织化学定位和高分辨电子显微镜检查，本提案的目的是更详细地研究这一问题。我们将使用一种反复、严重应激-重复束缚应激的啮齿动物模型来研究应激在BLA中的作用。我们将首先确定压力如何改变这些蛋白质在BLA中的定位的时间进程。接下来，我们将使用体外系统来评估这些蛋白质如何受到BLA中活动模式变化的影响，以及先前的应激暴露如何改变杏仁核对活动的反应。最后，我们将使用包埋后免疫金标记法来研究应激如何影响BLA中突触后密度的组成。这些研究将提供对BLA中兴奋性神经传递的分子结构的详细了解，并确定这种结构是如何被先前的应激暴露改变的。这些信息将加强我们对这一关键脑区应激影响的理解，并为包括创伤后应激障碍在内的应激相关疾病的新疗法提供可能的分子靶点。 公共卫生相关性： 压力在改变行为方面起着重要作用，并可能导致或恶化与退伍军人事务部临床任务相关的各种精神状况。压力会引发或加重抑郁症和各种不同的焦虑症。精神分裂症患者的压力与症状恶化有关。压力与酗酒、吸毒和依赖的复发有关。特别是，我们现在认识到，在平民和军人中，严重的应激源可能与创伤后应激障碍(PTSD)的发展有关。这些情况折磨着我们的大量退伍军人。大量资源已投入到这些患者的护理上，此外，这些疾病可能会增加患者对其他医疗问题的医疗资源的使用。虽然压力和压力相关疾病的重要性已经明确，但我们的治疗充其量仍然是部分有效的。在这里，我们建议进行研究，以更好地了解压力对大脑关键区域杏仁核的影响。杏仁核是参与创伤后应激障碍和大脑对压力反应的大脑区域。已有研究表明，压力会改变杏仁核的回路和功能。在这项提案中，我们将研究参与无节核兴奋性交流的关键分子的组织是如何因应激而改变的。拟议的研究结果将进一步加深我们对应激引起的杏仁核变化的理解，并为包括创伤后应激障碍在内的应激相关疾病的新药治疗提供特定的分子靶点。

DESCRIPTION (provided by applicant): Stress is a powerful stimulus that modulates animal behavior and the functioning of the nervous system. In people, stress negatively impacts a variety of psychiatric conditions relevant to the clinical mission of the Department of Veterans Affairs, including depression, anxiety and substance abuse. In particular, exposure to severe stress is associated with posttraumatic stress disorder (PTSD), both in military and civilian populations. These conditions are a major health issue for our veteran population and available treatments are at best partially effective. There is a pressing need to better understand the effect of stress on the functioning of the brain in order to design better treatments for stress related disorders. Studies in humans and animals have indicated that the amygdala is a brain region involved in mediating the behavioral responses to stress, and patients' with PTSD show elevated activity in this brain region. In particular the basolateral complex of the amygdala (BLA) is critical to normal and pathological amygdala functioning. The BLA's response to stress has been shown to involve synaptic plasticity of the excitatory, glutamatergic connections within this brain region. While complex synaptic plasticity is a complex phenomenon, many studies have indicated that it involves the NMDA and AMPA subtypes of glutamate receptor, as well as the signal transduction protein CaMKII. Manipulations that block the activity of these proteins block behavioral responses to stress. There is evidence that the response of these proteins to altered activity levels and stress involves altered patterns of localization. It is the goal of this proposal to study this issue in more detail using immunohistochemical localization of the NR1 and GluR1 subunits of the NMDA and AMPA receptors and CaMKII and high resolution electron microscopic examination. We will use a rodent model of repeated, severe stress- repeated immobilization stress to study the effect of stress in the BLA. We will begin by determining the time course of how stress alters the localization of these proteins in the BLA. We will next use an in vitro system to assess how these proteins are affected by altered activity patterns in the BLA and how prior stress exposure modifies the amygdala's response to activity. Finally, we will use post-embedding immunogold labeling to study how stress affects the composition of the postsynaptic density in the BLA. These studies will provide a detailed understanding of the molecular architecture of excitatory neurotransmission in the BLA and determine how this is altered by prior stress exposure. This information will enhance our understanding of stress affects in this critical brain region and suggest possible molecular targets for novel therapies for stress related disorders, including PTSD. PUBLIC HEALTH RELEVANCE: Stress plays a significant role in modifying behavior and may lead to, or worsen, a variety of psychiatric conditions relevant to the clinical mission of the Department of Veterans Affairs. Stress can precipitate or worsen episodes of depression and a variety of different anxiety disorders. Stress is associated with worsening symptoms in schizophrenia. Stress is associated with relapse in alcohol and drug abuse and dependence. In particular, we now recognize that severe stressors can be associated with the development of post-traumatic stress disorder (PTSD) in both civilian and military populations. These conditions afflict large numbers of our veteran population. Substantial resources have been committed to the care of these patients, and further, these disorders can increase a patient's use of healthcare resources for other medical problems. While importance of stress and stress related illnesses is clearly established, our treatments remain partially effective at best. Here we propose research to better understand the effect of stress in a critical brain region, the amygdala. The amygdala is a brain region involved in PTSD and the brain's response to stress. Stress has been shown to alter the circuitry and functioning of the amygdala. In this proposal we will investigate how the organization of key molecules, involved in excitatory communication in the amgygdala, is altered by stress. The results of the proposed studies will further our understanding of stress induced changes in the amygdala and suggest specific molecular targets for new drug treatments for stress related disorders, including PTSD.