Glucocorticoids and sensory neuron plasticity

项目摘要/摘要 本项目将研究糖皮质激素(GC)如何与感觉中的糖皮质激素受体(GRs)相互作用 神经元和神经胶质细胞影响神经损伤后疼痛的发展和维持。大多数研究 检查神经损伤引起的疼痛并不检查GC/GR相互作用在疼痛中的重要性 发展和/或如何促进损伤后出现的变化(例如反应性胶质细胞增多症)。因此，这一点 该项目与NIH的任务相关，因为它检查了GR在各种 神经系统细胞类型，并将阐明神经元发育所需的GR表达 过度兴奋和受伤后的疼痛。尽管脊髓损伤后GR表达增加， GR活性是否对下游反应是必要的尚未得到证实。因此，我们将使用 Cre-Lox系统评估有无升高的感觉神经元、小胶质细胞和星形胶质细胞的GR丢失 皮质酮水平，以确定GC/GR相互作用在哪里影响疼痛和神经元兴奋性。 广泛的感觉行为测试将确定每种细胞类型中GR的丢失是否会影响反射性和 自发性疼痛的形成和维持。三维组织清除技术将提供一种 使用CFO在脊髓和大脑中观察神经元兴奋性变化的总体视角，以及促进 外周和中枢感觉突起神经支配变化的可视化。中的更改 感觉神经元的兴奋性将使用膜片钳记录直接测量。胶质细胞激活基因 在每种情况下，都将对其进行广泛的形态检查。总而言之，这些数据将提供 对感觉神经元、小胶质细胞和星形胶质细胞中糖皮质激素受体生物学的基本认识 AS在损伤环境中辨别GR在神经元和神经胶质细胞中作用的重要性。

PROJECT SUMMARY/ABSTRACT This project will study how glucocorticoids (GCs) interact with glucocorticoid receptors (GRs) in sensory neurons and glia to effect the development and maintenance of pain after nerve injury. The majority of studies examining nerve-injury induced pain do not examine where GC/GR interactions are important for pain development and or how they contribute to the changes that arise after injury (e.g. reactive gliosis). Thus, this project is relevant to the NIH mission because it examines the fundamental importance of GRs in various nervous system cell types and will elucidate where GR expression is required for the development of neuronal hyperexcitability and pain after injury. Even though GR expression in the spinal cord increases after injury, whether GR activity is necessary for downstream responses has not been demonstrated. Thus we will use Cre-Lox systems to evaluate GR loss in sensory neurons, microglia and astrocytes with and without elevated corticosterone levels to determine where GC/GR interactions are influencing pain and neuronal excitability. Extensive sensory behavior testing will determine if loss of GR in each cell type effects reflexive and spontaneous pain development and maintenance. Three-dimensional tissue clearing techniques will provide an overarching view of neuronal excitability changes using cFOS in the spinal cord and brain, as well as facilitate the visualization of changes in sensory process innervation in the periphery and in the CNS. Changes in sensory neuron excitability will be directly measured using patch-clamp recording. Glial activation, gene expression, and morphology will be extensively examined in each condition. Together, these data will provide fundamental insight into glucocorticoid receptor biology in sensory neurons, microglia, and astrocytes as well as discern the importance of GR actions in neurons versus glia in an injury environment.