Amygdala pain mechanisms

项目摘要 慢性疼痛是一种复杂的多维疾病，仍然是一个主要的卫生保健问题和治疗挑战。这个 发展新的和改进的治疗策略需要充分了解慢性疼痛的机制 在神经轴的所有水平和所有类型的细胞，包括非神经元成分。神经免疫信号已经出现 作为一种外周和脊髓疼痛机制，但对其作用、调节和治疗潜力知之甚少。 在疼痛的背景下，大脑中神经元和神经胶质细胞类型之间的分子串扰。要解决这一重要问题 我们将在美国国立卫生研究院(NIH)资助的工作(自1999年以来)的基础上，通过确定神经可塑性来影响该领域的知识差距 在杏仁核，一个情绪的大脑中心，作为疼痛和疼痛的情绪情感方面的关键机制 调制。拟议中的项目将测试杏仁核可塑性的时序化和 神经病理性疼痛行为依赖于一系列神经免疫信号，这些信号可以被靶向缓解 神经性疼痛。具体地说，在急性疼痛阶段，某些类型的杏仁核神经元的突触驱动增强 激活不同类型的胶质细胞，而胶质细胞衍生因子在不同类型的杏仁核神经元中产生超兴奋性。 维持神经病理性疼痛的慢性期。将使用综合的多学科方法， 集成了最先进的转录学，生物信息学，行为分析，脑片电生理学， 药理学、化学遗传学、光遗传学、病毒载体策略、免疫组织化学和分子生物学 杏仁核内不同类型神经元和神经胶质细胞之间的神经免疫相互作用分析 在已建立的神经病理性疼痛的脊神经结扎(SNL)大鼠模型中，输出区域(中央核，CEA)。 将对雄性和雌性大鼠进行研究。转基因CRH-CRE大鼠模型将用于CEA促肾上腺皮质激素的研究 释放因子(CRF)系统在杏仁核可塑性中起重要作用，并在神经免疫信号中发挥作用。目标1 将使用细胞特异性批量和单细胞RNA测序(scRNA-Seq)相结合的方法来识别单个基因， 与疼痛时序化相关的分子途径和功能细胞状态。一种新的计算型scRNA-Seq- 基于相互作用组的分析将确定神经病理性疼痛急性期和慢性期的神经元-神经胶质细胞的相互作用 并确定药物靶向的分子因素。目的2将确定神经元-神经胶质-神经元的行为意义 神经病理性疼痛不同阶段CEA中的信号，利用不同细胞的化学激活和抑制 调节分子因子的类型和药理(或基于病毒的)工具。感觉阈值，情绪 将测量反应、非诱发性持续疼痛以及焦虑和抑郁样行为。目标3将决定 神经病理性疼痛不同阶段CEA中神经元-神经胶质-神经元信号的电生理机制， 使用脑片上不同细胞类型的膜片钳记录以及化学发生和药理(或病毒) 基于)操纵。成功完成这些概念上的创新研究将极大地推动我们的 神经免疫信号在大脑可塑性和从急性疼痛到慢性疼痛的转变中的知识 减轻慢性神经病理性疼痛的新靶点。

Project Summary Chronic pain, a complex multidimensional disorder, remains a major health care issue and a therapeutic challenge. The development of new and improved therapeutic strategies requires the full understanding of mechanisms of chronic pain at all levels of the neuraxis and for all cell types, including non-neuronal elements. Neuroimmune signaling has emerged as a peripheral and spinal pain mechanism, but little is known about the role, regulation and therapeutic potential of molecular crosstalk between neuronal and glial cell types in the brain in the context of pain. To address this important knowledge gap we will build on our NIH-funded work (since 1999) that impacted the field by identifying neuroplasticity in the amygdala, a brain center for emotions, as a critical mechanism for emotional-affective aspects of pain and pain modulation. The proposed project will test the novel hypothesis that chronification of amygdala plasticity and neuropathic pain behaviors depends on a cascade of neuroimmune signaling that can be targeted to mitigate neuropathic pain. Specifically, enhanced synaptic drive of certain amygdala neuron types at the acute pain stage activates different types of glia, and glia-derived factors generate hyperexcitability in distinct amygdala neuron types at the chronic stage to maintain neuropathic pain. A comprehensive multidisciplinary approach will be used that integrates state-of-the-art transcriptomics, bioinformatics, behavioral assays, brain slice electrophysiology, pharmacology, chemogenetics, optogenetics, viral vector strategies, immunohistochemistry and molecular biology for the analysis of neuroimmune interactions within and between different types of neuronal and glial cells in the amygdala output region (central nucleus, CeA) in the well-established spinal nerve ligation (SNL) rat model of neuropathic pain. Male and female rats will be studied. A transgenic Crh-Cre rat model will be used to study the CeA corticotropin releasing factor (CRF) system, an important player in amygdala plasticity, and its role in neuroimmune signaling. Aim 1 will use a combination of cell-specific bulk and single-cell RNA sequencing (scRNA-Seq) to identify individual genes, molecular pathways and functional cellular states associated with pain chronification. A novel computational scRNA-Seq- based interactome analysis will determine neuron-glia interactions at the acute and chronic stages of neuropathic pain and identify drug-targetable molecular factors. Aim 2 will determine the behavioral significance of neuron-glia-neuron signaling in the CeA at different stages of neuropathic pain, using chemogenetic activation and inhibition of different cell types and pharmacological (or viral based) tools to modulate molecular factors. Sensory thresholds, emotional responses, non-evoked ongoing pain, and anxiety- and depression-like behaviors will be measured. Aim 3 will determine electrophysiological mechanisms of neuron-glia-neuron signaling in the CeA at different stages of neuropathic pain, using patch-clamp recordings of different cell types in brain slices and chemogenetic and pharmacological (or viral based) manipulations. Successful completion of these conceptually innovative studies will significantly advance our knowledge of neuro-immune signaling in brain plasticity and in the transition from acute to chronic pain and provide novel targets to mitigate chronic neuropathic pain.