Understanding the functional anatomy of nociceptive spinal output neurons

项目总结/摘要 疼痛是一种使人衰弱的疾病，严重影响生活质量。尽管对新疗法的需求不断增长， 对疼痛神经回路的不完全理解限制了新疼痛的发展 治疗学脊髓背角浅通道中的脊髓投射神经元 进入大脑。这些神经元可能代表未来疼痛管理策略的可行目标。虽然几乎 所有介导伤害性感受的脊髓输出神经元都靶向对侧臂旁核， 这些神经元也投射到其他脊髓上结构，例如同侧臂旁核（spino-brachial nucleus， PBN神经元）或对侧导水管周围灰质（脊髓PAG神经元）。鉴于不同的抵押品 这些神经元的模式，我假设，脊髓PBN和脊髓PAG神经元有不同的 伤害感受功能我将使用解剖学（目标1）、功能（目标2）和行为（目标3）来检验这一假设。 (Aim（3）方法。目的1研究脊髓PAG和脊髓PBN神经元的投射模式 通过逆行病毒追踪、光学清除和带状扫描共聚焦显微镜。目标2将决定 利用双光子钙成像研究脊髓PAG和脊髓PBN神经元的功能反应特性 和应用于离体制剂的天然刺激物。目的3将揭示spino-PAG和spino-PAG的作用， 使用化学遗传学和伤害感受的行为测定介导伤害性行为的PBN神经元。的 在这个提议中描述的实验有可能推进我们对脊髓输出的基本理解 回路介导伤害性感受，并帮助确定脊髓投射神经元作为新靶点的功效， 临床干预。为了完成这份建议书，我将接受来自一个 专家科学家和临床医生导师团队。这次培训将使我成为一个独立的 调查员，让我实现了我的长期目标，成为一名专门研究疼痛的医生科学家。

Project Summary/Abstract Pain is a debilitating condition that severely impacts quality of life. Despite a growing need for new treatments, an incomplete understanding of the neural circuitry underlying pain has limited the development of novel pain therapeutics. Spinal projection neurons in the superficial dorsal horn channel pain signals from the spinal cord into the brain. These neurons may represent a viable target for future pain management strategies. While virtually all the spinal output neurons mediating nociception target the contralateral parabrachial nucleus, subsets of these neurons also project to other supraspinal structures, such as the ipsilateral parabrachial nucleus (spino- PBN neurons) or the contralateral periaqueductal gray (spino-PAG neurons). Given the distinct collateralization patterns of these neurons, I hypothesize that the spino-PBN and spino-PAG neurons have distinct nociceptive functions. I will test this hypothesis using anatomical (Aim 1), functional (Aim 2), and behavioral (Aim 3) approaches. Aim 1 will characterize the projection patterns of the spino-PAG and spino-PBN neurons through retrograde viral tracing, optical clearing, and ribbon scanning confocal microscopy. Aim 2 will determine the functional response properties of the spino-PAG and spino-PBN neurons using two-photon calcium imaging and natural stimuli applied to an ex vivo preparation. Aim 3 will uncover the role of the spino-PAG and spino- PBN neurons in mediating nocifensive behavior using chemogenetics and behavioral assays of nociception. The experiments described in this proposal have the potential to advance our basic understanding of the spinal output circuitry mediating nociception and help determine the efficacy of spinal projection neurons as new targets for clinical intervention. To complete this proposal, I will receive rigorous intellectual and technical training from a team of expert scientist and clinician mentors. This training will enable me to become an independent investigator, allowing me to accomplish my long-term goal of becoming a physician-scientist specializing in pain.