Molecular genetic dissection of the spinal microcircuits of wind-up

缠绕脊髓微电路的分子遗传学解剖

• 批准号: 9246779
• 负责人: H Richard Koerber
• 金额: $ 42.47万
• 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: 2016-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9246779
• 关键词: Address; Affect; Afferent Neurons; Alleles; American; Behavioral Mechanisms; Behavioral Model; Biological Neural Networks; C Fiber; Chemosensitization; Cutaneous; Development; Dissection; Dorsal; Environmental Wind; Esthesia; Frequencies; Genetic; Goals; Health; Hyperalgesia; Injury; Interneurons; Knowledge; Label; Ligation; Measures; Mediating; Mediator of activation protein; Modeling; Molecular Genetics; Mus; Nerve; Neurons; Neurotensin; Nociception; Output; Pain; Pain management; Patients; Perception; Peripheral; Peripheral Nervous System Diseases; Persistent pain; Pharmacologic Substance; Physiological; Play; Population; Preparation; Process; Research; Role; Sensory; Sensory Process; Skin; Specificity; Spinal; Spinal Cord; Spinal nerve structure; Stimulus; Symptoms; Synapses; Testing; Time; allodynia; base; behavioral response; cell type; chronic neuropathic pain; chronic pain; clinically relevant; effective intervention; effective therapy; experience; improved; information processing; injured; innovation; insight; nerve injury; neural circuit; neuroregulation; new therapeutic target; novel; novel therapeutics; optogenetics; programs; relating to nervous system; response; sensory input; sensory mechanism; somatosensory; tool

Chronic pain is a debilitating condition that affects one in four Americans, and for which there is a pressing need for safe, effective treatments. Chronic pain patients experience enhanced pain sensations and often experience pain when innocuous stimuli are presented. However, the neural basis for this amplification is poorly understood. Here, we propose to investigate the neural circuit basis for wind-up, a physiological type of central hyperexcitability that may also contribute to persistent pain. The studies we are proposing will begin to identify specific spinal circuitry involved in this amplification, and investigate whether these microcircuits are altered in conditions of injury. This knowledge may elucidate new therapeutic targets for the treatment of pain, which is the long-term goal of research of our program. In the first aim, we will use our novel skin/nerve/DRG/spinal cord preparation combined with optogenetic approaches to examine the involvement of select cell types in wind-up of cutaneous sensory inputs recorded in spinal projection neurons. These studies will examine the roles of specific subsets of cutaneous sensory neurons in wind-up by optogenetic stimulation of their cutaneous projections both in naïve mice and following nerve injury. We will also employ optogenetic strategies to activate or inhibit specific subsets of genetically defined excitatory (neurotensin (Nt)-cre) and inhibitory (nNos-creER) spinal interneurons to determine their roles in this process. In the second aim we will examine potential neural network and/or synaptic mechanisms underlying the wind-up of sensory inputs. In particular, we will test the role of persistent, reverberating currents in wind-up. In addition, investigate which mediators cause the slow depolarizing current that is often observed with wind-up, and determine whether this plays a contributing role. In the third aim, we will use a novel behavioral model of wind-up using temporal summation of cutaneous sensory inputs. Specifically, we have developed a behavioral model of temporal summation in mice using the same optogenetic stimulation that we previously used to induce wind-up in the first aim. This will allow us, for the first time, to make a direct correlation between the physiological phenomenon (wind-up) and a behavioral response to the perception of pain (temporal summation), using place-aversion as a measure of nociception in mice. Completion of the studies proposed in this application will provide new insights into spinal circuitry underlying the processing of sensory information, and how these processes are altered following nerve injury. Importantly could provide potential targets for the development of pharmaceutical therapies. These new therapies could provide for improved treatments for the alleviation of the adverse symptoms of chronic neuropathic pain.

慢性疼痛是一种使人衰弱的状况，影响了四分之一的美国人，并且有一个紧迫的 需要安全有效的治疗。慢性疼痛患者经常会增加疼痛感，并且经常 出现无害刺激时会经历痛苦。但是，这种扩增的神经基础是 理解不佳。在这里，我们建议调查Wind-Up的神经回路基础，一种物理类型 中央过度兴奋性也可能导致持续性疼痛。我们提出的研究将开始 确定与此扩增有关的特定脊柱回路，并研究这些微电路是否为 受伤状况改变。这些知识可以阐明用于治疗疼痛的新的治疗靶点， 这是我们计划研究的长期目标。在第一个目标中，我们将使用我们的小说 皮肤/神经/DRG/脊髓制剂与光遗传学方法相结合，以检查 在脊柱投射神经元中记录的皮肤感觉输入的发条中选择细胞类型。这些研究 将通过光遗传学刺激来检查皮肤感觉神经元特异性子集在发条中的作用 在幼稚的小鼠和神经损伤后，它们的皮肤投射。我们还将采用光遗传学 激活或抑制遗传定义兴奋性（Neurotensin（NT）-CRE）和 抑制性（NNOS-CREER）脊柱中间神经元在此过程中确定其作用。在第二个目标中，我们将 检查感官输入引流的潜在神经网络和/或突触机制。在 特别是，我们将测试持续，回荡电流在发条中的作用。另外，调查哪个 介体导致经常通过发条观察到的缓慢分裂电流，并确定是否 发挥作用。在第三个目标中，我们将使用临时性的新型行为模型 皮肤感觉输入的总和。具体而言，我们已经开发了临时行为模型 使用相同的光遗传刺激在小鼠中求和，我们以前用来诱导在 第一个目标。这将使我们第一次达到生理学之间的直接相关性 现象（结算）和对疼痛感知的行为反应（时间求和），使用 位置的衡量小鼠伤害感受。在本申请中提出的研究的完成将 提供有关感官信息处理基础的脊柱电路的新见解，以及如何 神经损伤后的过程发生了改变。重要的是，可以为开发的潜在目标提供 药物疗法。这些新疗法可以改善治疗方法以减轻 慢性神经性疼痛的不良症状。