Trans-synaptic signaling complex in amygdala pain mechanisms

摘要： 疼痛是一个严重的临床问题，影响着1亿多美国人。痛苦的经济代价是 估计超过几千亿美元，包括医疗成本和生产力损失。持久化 疼痛可能会导致长期的残疾，并导致抑郁、焦虑和认知障碍的沉淀。 目前使用的治疗慢性疼痛的药物并不总是有效的，在耐受性和滥用方面存在局限性 责任。因此，确定新的治疗靶点对于解决这一临床负担至关重要。外围和中央 编码、传递和放大或减少疼痛信号的通路已经被识别，包括脊髓丘脑和 脊臂神经通路。脊髓臂-杏仁核关键节区谷氨酸能突触的可塑性 通路在痛觉调制和从亚急性疼痛向慢性疼痛的转变中起着重要作用。然而， 该系统的发育、维持和可塑性的调控机制及其在疼痛持续中的作用 人们对其行为仍知之甚少。这项拟议的研究将提出跨突触信号的概念 以谷氨酸三角洲1受体为中心的复合体对中枢囊外侧区突触功能的调节 杏仁核也被称为“伤害性杏仁核”，与持续性疼痛机制有关。特定的Aim1将 明确这些受体的细胞类型和投射特异性分布及其在调节杏仁核回路中的作用 正常情况下的敌意和反感行为。具体目标2将决定持久性/慢性 用炎症和神经病理性疼痛模型检测谷氨酸-β1信号的疼痛相关变化 疼痛模型中突触神经可塑性的抢救策略。疼痛时杏仁核突触超微结构的变化 模型将使用3D电子显微镜进行评估。具体目标3将确定恢复反式反应的效果 谷氨酸-β1受体介导的突触信号在减轻痛觉知觉和厌恶情感行为中的作用 模特们。补充实验将解决中央杏仁核细胞类型特异性操作的影响 在减轻疼痛中的回路。为了实现这些目标，我们将利用脑片电生理学的组合， 行为、化学和光遗传学、共聚焦显微镜和电子显微镜(免疫和3D)以及遗传方法 确定谷氨酸-β1信号复合体调节的功能和结构机制 疼痛相关的神经可塑性和行为。这个项目意义重大，因为它将确定一种新的大脑机制 疼痛可以作为疼痛治疗的目标。科学严谨的研究设计是通过使用多个 方法和方法，在独立实验室复制实验，使用经过验证的模型和试剂， 除了考虑实验设计的其他方面外，还要考虑失明、生物变量和性别。

Summary: Pain is a serious clinical problem that affects more than 100 million Americans. The economic costs of pain have been estimated to be more than several hundred billion dollars including healthcare costs and lost productivity. Persistent pain may produce long-term disability and lead to precipitation of depression, anxiety and cognitive impairment. Currently used medications for chronic pain are not always effective and have limitations in terms of tolerance and abuse liability. Thus, identifying novel therapeutic targets is essential to address this clinical burden. Peripheral and central pathways that encode, transmit, and amplify or reduce pain signals have been identified, including the spinothalamic and spinoparabrachial pathways. Plasticity of glutamatergic synapses along key nodes in the spinoparabrachial-amygdala pathway plays an important role in pain modulation and in the transition from subacute to chronic pain. However, the mechanisms governing the development, maintenance and plasticity of this system and their role in persistence of pain behaviors remain poorly understood. The proposed research will advance the concept that the trans-synaptic signaling complex centered on glutamate delta 1 receptor regulates function of synapses in the laterocapsular region of central amygdala also known as “nociceptive amygdala” and contributes to persistent pain mechanisms. Specific Aim1 will define the cell type- and projection-specific distribution of these receptors and their role in regulating amygdala circuitry and nocifensive and averse-affective behavior under normal conditions. Specific Aim 2 will determine persistent/chronic pain-related changes in glutamate delta 1 signaling using inflammatory and neuropathic pain models and test the effect of a rescue strategy on synaptic neuroplasticity in pain models. Changes in ultrastructure of amygdala synapses in pain models will be evaluated using 3D-electron microscopy. Specific Aim 3 will determine the effect of restoring trans- synaptic signaling through the glutamate delta 1 receptor in mitigating nocifensive and averse-affective behaviors in pain models. Complementary experiments will address the effect of cell-type specific manipulation of central amygdala circuitry in mitigating pain. To accomplish these aims we will utilize a combination of brain slice electrophysiology, behavior, chemo- and opto-genetics, confocal and electron microscopy (immuno and 3D), and genetic approaches to determine the functional and structural mechanisms through which the glutamate delta 1 signaling complex regulates pain-related neuroplasticity and behaviors. This project is significant because it would identify a novel brain mechanism of pain that could be targeted for pain management. Scientific rigor of research design is established by the use of multiple methods and approaches, replication of experiments in independent laboratories, use of validated models and reagents, consideration of blinding, biological variables and sex in addition to other aspects of experimental design.