The study of the pain mechanisms using rat dorsal root ganglia

背根神经节（DRG）神经元和相关的初级传入神经传递不同的感觉方式，包括伤害性感受，脊髓背角。在初级传入神经元上发现了多种类型的神经元细胞，包括在它们的中枢突起、外周突起和背根节细胞的胞体上，并发现了几种GPCR，包括P物质受体、毒蕈碱受体、5-HT_2受体和食欲素受体。因此，背根神经节已被用于研究伤害性感受。这是感兴趣的，以确定药物对这些受体的作用，我们研究了谷氨酸受体在DRG中的作用和麻醉剂对非洲爪蟾卵母细胞中表达的mGluR 1和mGluR 5的功能的影响。我们研究了氟烷，异氟烷，恩氟烷，乙醚，和乙醇对SP诱导的电流介导的SPR表达在非洲爪蟾卵母细胞，通过使用全细胞电压钳。所有的挥发性麻醉药和乙醇都能抑制SPR诱导的Ca（2+） ...更多信息 ）激活的Cl（-）电流。神经甾体阿法沙龙可抑制乙酰胆碱（Ach）介导的爪蟾卵母细胞M（1）和M（3）受体的反应，而DHEA则无此作用。此外，我们检查了右美托咪定在该系统中的作用。右美托咪定不影响表达相应受体的卵母细胞中5-HT_2c-、P物质-或食欲素A诱导的Cl^-电流。在表达M_1受体的非洲爪蟾卵母细胞上，该化合物对乙酰胆碱（Ach，1μM）诱导的Ca^<2+>激活的C1^-电流也几乎没有影响。相反，右美托咪定抑制表达M_3受体的非洲爪蟾卵母细胞的Ach-induced电流。用选择性蛋白激酶C抑制剂GF 109203 X处理后，右美托咪定可降低Ach诱导的C1^-电流。此外，该化合物以浓度依赖性方式抑制培养的DRG细胞中毒蕈碱受体介导的[Ca^2+]增加。提示背根神经节谷氨酸受体可能在痛觉传递中起重要作用。少

The dorsal root ganglion (DRG) neurons and associated primary afferent nerves transmit different sensory modalities, including nociception, to the spinal dorsal horn. Many types of neuronal cell have been found on primary afferent neurons, either on their central or peripheral processes or on the cell bodies of DRG cells and the presence of several GPCRs has been reported, including substance P, muscarinic, 5-HT_2 and orexin receptors. Consequently, the DRG has been used to study nociception. It is of interest to determine drug actions on these receptors, and we investigated the role of the glutamate receptor in DRG and the effects of anesthetics on the function of mGluR1 and mGluR5 expressed in Xenopus laevis oocytes. We examined the effects of halothane, isoflurane, enflurane, diethyl ether, and ethanol on SP-induced currents mediated by SPR expressed in Xenopus oocytes, by using a whole-cell voltage clamp. All the volatile anesthetics tested, and ethanol, inhibited SPR-induced Ca(2+ … More )-activated Cl(-) currents at pharmacologically relevant concentrations. Neurosteroid, alphaxalone, inhibited the acetylcholine (Ach)-mediated responses of M(1) and M(3) receptors expressed in Xenopus oocytes, whereas DHEA did not. Moreover, we examined the the effects of Dexmedetomidine in this systems. Dexmedetomidine did not affect the 5-HT_2c-, substance P-, or orexin A-induced Cl^- currents in oocytes expressing the respective receptors. The compound also had little effect on the acetylcholine (Ach, 1μM)-induced Ca^<2+>-activated C1^- currents in Xenopus oocytes expressing M_1 receptors. In contrast, dexmedetomidine inhibited the Ach-induced currents in Xenopus oocytes expressing M_3 receptors. Dexmedetomidine reduced the Ach-induced C1^- currents after treatment with the selective protein kinase C inhibitor GF109203X. Moreover, the compound inhibited the muscarinic receptor-mediated increases in [Ca^<2+>; in cultured DRG cells in a concentration-dependent manner. From these results, the glutamate receptors may play the important role in pain transmission in DRG. Less