Understanding the spinal circuitry of cold

了解寒冷的脊髓回路

• 批准号: 10063581
• 负责人: Tayler Sheahan
• 金额: $ 10.21万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-12-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10063581
• 关键词: Address; Alleles; Architecture; Behavioral; Behavioral Assay; Brain; Cations; Cells; Classification; Collaborations; Cutaneous; Data; Electrophysiology (science); Esthesia; Felis catus; Fellowship; Foundations; Future; Genetic; Goals; Health; Histology; Hypersensitivity; Impairment; K-Series Research Career Programs; Knowledge; Label; Left; Mechanics; Mediating; Modality; Morphology; Mus; Nervous system structure; Neuraxis; Neurokinin A; Neurons; Neuropeptide Receptor; Pain; Pain Clinics; Pain Research; Pathologic; Pattern; Physiologic Thermoregulation; Population; Positioning Attribute; Preparation; Process; Research; Role; Sensory; Spinal; Spinal Cord; Spinal cord posterior horn; Stimulus; Substance P; Substance P Receptor; Synapses; TRP channel; Temperature; Testing; Tetrodotoxin; Tissues; Training; base; behavioral response; biocytin; career development; disabling symptom; effective therapy; experimental study; extreme temperature; neural circuit; optogenetics; painful neuropathy; patch clamp; response; somatosensory; success

Cutaneous thermosensation is critical for detecting and avoiding potentially harmful environmental temperatures, as well as thermoregulation. This mechanism frequently goes awry under neuropathic pain conditions, manifesting as cold hypersensitivity, a condition in which normally cool input is perceived as painfully cold. A limited understanding of how cold stimuli are encoded in the nervous system has left this debilitating condition poorly managed. Recent studies suggest that cold input is conveyed from the periphery to the central nervous system by a population of primary afferents that express the temperature-sensitive cation channel TRPM8. However, the neural circuits through which this information is processed in the spinal cord and conveyed to the brain remain almost completely unknown. To address this fundamental gap in knowledge, this proposal will dissect the neural circuitry that encodes cold stimuli through a combination of behavioral, electrophysiological and morphological approaches. Based on our preliminary studies, we believe that cold input is conveyed from the spinal cord to the brain by a subset of neurokinin 1 receptor (NK1R)-expressing spinoparabrachial projection neurons. To investigate this possibility, our lab recently generated a NK1R-CreER allele, thereby providing us with genetic access to label and manipulate the activity of NK1R neurons. This proposal will test the hypothesis that cold input is conveyed from the spinal cord to the brain by a subset of morphologically distinct NK1R neurons that receive synaptic input (direct or indirect) from cold-sensing, TRPM8 primary sensory afferents. Aim 1 will investigate whether NK1R spinal projection neurons are required for aversion to cold using behavioral assays. Aim 2 will dissect the circuitry between TRPM8 primary afferents and NK1R spinal projection neurons that respond to cold stimuli using electrophysiology and optogenetic approaches in combination with our ex vivo somatosensory preparation. Aim 3 will determine the morphology of cold-selective spinal projection neurons by using histology to reconstruct cell architecture within the spinal cord dorsal horn. These experiments will establish the basic spinal circuitry that mediates cold input, thereby providing a framework from which to investigate changes in circuitry that underlie cold hypersensitivity in future studies. The success of this multifaceted fellowship training plan, which includes activities for scientific and career development, will be aided by the scientific expertise, collaboration, and educational opportunities offered by the Pittsburgh Center for Pain Research.

皮肤热敏度对于检测和避免潜在有害环境温度至关重要， 以及温度调节。在神经性疼痛条件下，这种机制经常出现问题， 表现为冷血过敏，通常认为凉爽的输入是痛苦的。一个 对神经系统中冷刺激的编码方式的了解有限 管理不善。最近的研究表明，冷输入从外围传达到中枢神经 由表达温度敏感阳离子通道TRPM8的主要传入的系统。 但是，在脊髓中处理该信息并传达给该信息的神经回路 大脑几乎完全未知。为了解决这一知识的基本差距，该建议将 解剖通过行为，电生理学的组合来编码冷刺激的神经回路 和形态学方法。根据我们的初步研究，我们认为感冒输入是从 通过表达旋转的旋转旋转的一部分神经蛋白1受体（NK1R）的子集进入大脑的脊髓 神经元。为了调查这种可能性，我们的实验室最近生成了NK1R-Creer等位基因，从而为我们提供 随着遗传获取标记并操纵NK1R神经元的活性。该建议将检验假设 冷输入通过形态上不同的NK1R神经元的子集从脊髓传达到大脑 从冷感应，TRPM8主要感觉传入中，接收突触输入（直接或间接）。目标1意志 研究是否需要使用行为测定法冷冷的NK1R脊柱投射神经元。 AIM 2将剖析TRPM8初级传入和NK1R脊柱投影神经元之间的电路 使用电生理学和光遗传学方法对冷刺激作出反应 体感准备。 AIM 3将确定冷选择性脊柱投射神经元的形态 使用组织学在脊髓背角内重建细胞结构。这些实验将建立 介导冷输入的基本脊柱电路，从而提供了一个框架来调查 在未来的研究中，电路的变化是寒冷的超敏反应。这个多方面的成功 奖学金培训计划包括科学和职业发展的活动，将由 匹兹堡痛苦中心提供的科学专业知识，协作和教育机会 研究。