Satellite glial cells in sensory ganglia: Their possible contribution to inflammatory pain
Satellite glial cells in sensory ganglia: Their possible contribution to inflammatory pain
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DOI：
10.1016/j.bbi.2006.11.011
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发表时间：
2007-07-01
影响因子：
15.1
通讯作者：
Hanani, Menachem
中科院分区：
文献类型：
--
作者：
Dublin, Pavel;Hanani, Menachem
背根神经节（DRG）中的神经元被卫星胶质细胞（SGCs）包围。关于SGC生理学及其与神经元的相互作用知之甚少。在这项工作中，我们研究了小鼠DRG神经元和SGC的变化后，诱导炎症的后爪注射完全弗氏佐剂（CFA）。神经元的电生理特性由细胞内电极表征。SGCs之间的间隙连接介导的耦合的变化进行了监测，使用荧光染料荧光黄的细胞内注射。用von Frey毛发评估疼痛。我们发现，CFA注射后两周，DRG神经元中激发动作电位的阈值降低了38%，与神经元过度兴奋一致。荧光黄注射到SGCs显示，与对照组相比，周围的相邻神经元SGCs之间的缝隙连接耦合增加2.7-，3.2-和2.5倍，分别在CFA注射后一周，两周和一个月。在投射到发炎的爪子中的包裹神经元的SGCs中，这种作用更增强（5.4倍）。CFA注射后，神经元间的耦合增加了7%。在注射CFA后一周、两周和一个月，与对照组相比，注射爪的疼痛阈值分别降低了13%、16%和11%。腹腔注射差距连接阻断剂甘珀酸可防止炎症引起的痛阈降低。结果表明，胶质细胞偶联增强是炎症后DRG中发生的主要事件之一。甘珀酸给药后痛阈的升高为细胞间偶联增强可能导致慢性疼痛的观点提供了间接支持。(c)2006年爱思唯尔公司All rights reserved.
Neurons in dorsal root ganglia (DRG) are surrounded by an envelope of satellite glial cells (SGCs). Little is known about SGC physiology and their interactions with neurons. In this work, we investigated changes in mouse DRG neurons and SGC following the induction of inflammation in the hind paw by the injection of complete Freund's adjuvant (CFA). The electrophysiological properties of neurons were characterized by intracellular electrodes. Changes in coupling mediated by gap junctions between SGCs were monitored using intracellular injection of the fluorescent dye Lucifer yellow. Pain was assessed with von Frey hairs. We found that two weeks after CFA injection there was a 38% decrease in the threshold for firing an action potential in DRG neurons, consistent with neuronal hyperexcitability. Injection of Lucifer yellow into SGCs revealed that, compared with controls, coupling by gap junctions among SGCs surrounding adjacent neurons increased 2.7-, 3.2-, and 2.5-fold one week, two weeks, and one month, respectively, after CFA injection. In SGCs enveloping neurons that project into the inflamed paw this effect was more enhanced (5.4-fold). Interneuronal coupling was augmented by up to 7% after CFA injection. Pain threshold in the injected paw decreased by 13%, 16%, and 11% compared with controls at one week, two weeks, and one month, respectively, after CFA injection. Intraperitoneal injection of the gap junction blocker carbenoxolone prevented the inflammation-induced decrease in pain threshold. The results show that augmented glial coupling is one of the major events occurring in DRG following inflammation. The elevation in pain threshold after carbenoxolone administration provides indirect support for the idea that augmented intercellular coupling might contribute to chronic pain. (c) 2006 Elsevier Inc. All rights reserved.