Comprehensive Phenotyping of Specific Populations of Spinal Neurons Processing Cutaneous Information Before and After Injury

损伤前后处理皮肤信息的脊髓神经元特定群体的综合表型

• 批准号: 10211006
• 负责人: H Richard Koerber
• 金额: $ 59.21万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-16 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10211006
• 关键词: Acute; Address; Agonist; American; Brain; Calcium; Capsaicin; Catalogs; Cells; Chemicals; Chronic; Cicadas; Code; Coupled; Cutaneous; Data; G-Protein-Coupled Receptors; Goals; Hand; Health; Hyperalgesia; Image; Individual; Injury; Knowledge; Label; Measures; Mechanics; Modeling; Mus; Nerve; Neurons; Neuropathy; Nociception; Optics; Output; Pain; Pain management; Patients; Peripheral; Persistent pain; Pharmaceutical Preparations; Pharmacology; Phenotype; Physiological; Population; Preparation; Process; Property; Research; Sensory; Series; Skin; Spinal; Spinal Cord; Stimulus; Testing; Tetrodotoxin; Thermal Hyperalgesias; Transgenic Mice; allodynia; base; calcium indicator; cell type; central sensitization; chronic pain; dorsal horn; effective therapy; excitatory neuron; experience; heat stimulus; imaging approach; imaging study; injured; innovation; insight; nerve injury; neural circuit; new therapeutic target; novel; novel strategies; pain chronification; pain sensation; programs; receptor; recruit; relating to nervous system; response; sensory input; sensory stimulus; somatosensory; spared nerve; tool; two-photon

ABSTRACT Chronic pain is a debilitating condition for which there is a pressing need for safe, effective treatments. These patients experience enhanced pain sensations and often experience pain when innocuous stimuli are presented. However, the neural basis for this increased sensitivity is poorly understood. Here, we propose to investigate the neural circuit basis for central hyperexcitability that may contribute to persistent pain. We will be combining novel physiological, and pharmacological approaches to address our goals. Using existing transgenic mouse lines, we can express the calcium indicator GCamp6s in all excitatory spinal neurons. We can then use our novel ex vivo skin-spinal cord preparation and 2-photon calcium imaging to examine activity in the spinal dorsal horn activity to cutaneous stimulation in naïve mice and those following injury. While this approach will allow us to image the responses of many (~200) neurons simultaneously, it does not allow us to identify different types of neurons, thereby severely hampering the degree to which the data can be interpreted. Now, we have developed a novel approach to circumvent this limitation through post hoc pharmacological identification of cell types. The underlying concept is that most neurons express one or more Gq-coupled G-protein coupled receptors (GPCRs) whose activation results in the release of Ca2+ from internal stores. In the presence of tetrodotoxin (TTX) to silence neuronal activity, the only neurons that show a Ca2+ transient in response to a given agonist are those that express its receptor. This approach, which we have termed CICADA (Cell-type Identification by Ca2+-coupled Activity through Drug Activation), allows us to unambiguously define cell types based on their responses to a series of GPCR agonists. Now we are uniquely poised to address specific questions about the function of spinal circuitry and how the functional properties of these circuits are altered following injury. In the first Aim we will extend and validate this analysis with the goal of developing a complete repertoire dorsal horn subtypes that can be identified in population imaging studies. While neurons respond to different types of sensory stimuli (e.g., heat, cold, and mechanical), how this coding is manifest across neuronal populations is unclear. In the second Aim we will catalog functional response properties across populations of CICADA-defined cell subtypes. In the third Aim we will examine the effects of capsaicin induced acute central sensitization on these subpopulations. The chronification of pain is thought to be associated with long-term changes in central network activity that perpetuate hyperalgesic states. In the fourth Aim we will identify the CICADA-defined cell types that show altered activity in the context of chronic pain using the spared nerve injury (SNI) as a model. The studies we are proposing here will begin to identify specific spinal circuitry involved in central sensitization and investigate how these specific microcircuits are altered in conditions of acute and chronic injury. This knowledge may elucidate new therapeutic targets for the treatment of pain, which is the long-term goal of research of our program.

抽象的 慢性疼痛是一种令人衰弱的状况，需要对这些疼痛进行安全有效的治疗。 当无害的刺激时，患者会感到疼痛增强，并且经常会出现疼痛 但是，提高敏感性的新的基础是糟糕的联盟。 研究中央过度刺激的神经回路，这可能会导致我们持续的疼痛 结合新颖的生理和药理学方法来解决我们的目标。 转基因小鼠线，我们可以在所有排斥性脊髓神经元中表达钙指示器 十个可以使用我们的小说外脊髓 在脊柱背角活性中，在幼稚和受伤后的皮肤刺激中。 方法将使我们同时对许多（〜200）神经元的反应进行想象，它不允许我们 识别不同类型的神经元，它们会严重阻碍数据可能为数据 解释了。 细胞类型的药理学识别。 GQ耦合的G蛋白偶联受体（GPCR），其激活导致Ca2+从内部释放 商店。 响应给定激动剂的转移是表达其受体的。 称为CICADA（通过Ca2+偶联活性通过药物激活鉴定细胞类型），使我们能够 明确根据细胞类型对一系列GPCR激动剂的响应来定义细胞类型。 准备解决有关脊柱电路功能的特定问题以及如何达到的功能特性 这些电路在第一个目标中受伤。 开发可以识别成像研究的成像背角亚型。 神经元对不同类型的感觉刺激（例如热，冷和机械）做出反应 在第二个目标中，在神经元流行的情况下表现出来。 CICADA定义的细胞亚型种群之间的特性。 辣椒素在亚挑选上诱导急性中央敏化。 与中央网络活动的长期变化有关，使痛觉状态存在 第四目的我们将确定蝉定义的细胞类型，这些细胞类型在慢性的背景下显示出改变活动的变化 我们在这里提出的研究的疼痛（SNI）将开始识别 涉及中央敏化涉及的特定脊柱回路，并研究了三个特定的微电路 急性和慢性损伤的状况改变了。 治疗疼痛，这是我们计划研究的长期目标。