Department of Anesthesiology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
Department of Psychological and Brain Science, Indiana University Bloomington, 702 N Walnut Grove Ave., Bloomington, IN, 47405, USA.
Neurosci Bull. 2018 Feb;34(1):85-97. doi: 10.1007/s12264-017-0142-1. Epub 2017 May 22.
Injury to peripheral nerves can lead to neuropathic pain, along with well-studied effects on sensory neurons, including hyperexcitability, abnormal spontaneous activity, and neuroinflammation in the sensory ganglia. Neuropathic pain can be enhanced by sympathetic activity. Peripheral nerve injury may also damage sympathetic axons or expose them to an inflammatory environment. In this study, we examined the lumbar sympathetic ganglion responses to two rat pain models: ligation of the L5 spinal nerve, and local inflammation of the L5 dorsal root ganglion (DRG), which does not involve axotomy. Both models resulted in neuroinflammatory changes in the sympathetic ganglia, as indicated by macrophage responses, satellite glia activation, and increased numbers of T cells, along with very modest increases in sympathetic neuron excitability (but not spontaneous activity) measured in ex vivo recordings. The spinal nerve ligation model generally caused larger responses than DRG inflammation. Plasticity of the sympathetic system should be recognized in studies of sympathetic effects on pain.
周围神经损伤可导致神经性疼痛，并对感觉神经元产生一系列已被深入研究的影响，包括过度兴奋、异常自发性活动以及感觉神经节的神经炎症。交感活动可增强神经性疼痛。周围神经损伤还可能损伤交感轴突或使其暴露于炎症环境中。在这项研究中，我们检查了两种大鼠疼痛模型对腰椎交感神经节的反应：L5 脊神经结扎和 L5 背根神经节（DRG）局部炎症，后者不涉及轴突切断。两种模型均导致交感神经节发生神经炎症变化，表现为巨噬细胞反应、卫星胶质细胞激活以及 T 细胞数量增加，同时在离体记录中测量到交感神经元兴奋性（但自发性活动无明显增加）。与 DRG 炎症相比，脊神经结扎模型通常引起更大的反应。在研究交感神经对疼痛的影响时，应认识到交感系统的可塑性。
