Prostaglandin E2 potentiates the excitability of small diameter trigeminal root ganglion neurons projecting onto the superficial layer of the cervical dorsal horn in rats
Prostaglandin E2 potentiates the excitability of small diameter trigeminal root ganglion neurons projecting onto the superficial layer of the cervical dorsal horn in rats
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DOI：
10.1007/s00221-006-0608-2
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发表时间：
2007-01-01
影响因子：
2
通讯作者：
Matsumoto, S.
中科院分区：
文献类型：
--
作者：
Kadoi, Jun;Takeda, M.;Matsumoto, S.
本研究的目的是利用荧光逆行示踪和穿孔膜片钳技术，研究前列腺素 E-2 (PGE(2)) 如何影响投射到颈背角浅层的三叉神经根神经节 (TRG) 神经元的兴奋性。 TRG 神经元用荧光金 (FG) 逆行标记。 FG标记的神经元的细胞直径很小(<30μm)。在电压钳模式下，PGE（2）（0.01-10μM）的应用浓度依赖性地增加了峰值抗河豚毒素钠电流（TTX-R I-Na）的大小，并且该电流在1μM浓度时达到最大。一微摩尔PGE（2）的应用导致TTX-R I-Na激活曲线中8.3 mV的超极化偏移。在电流钳模式下，PGE(2) (1 μM) 的应用显着增加了去极化阶跃脉冲期间的动作电位数量以及过冲水平，但对静息膜电位没有显着影响。这些结果表明，应用 1 μM PGE(2) 后观察到的小直径 TRG 神经元的兴奋性与 TTX-R I-Na 的增加有关。
The aim of the present study was to investigate how prostaglandin E-2 (PGE(2)) affects the excitability of trigeminal root ganglion (TRG) neurons, projecting onto the superficial layer of the cervical dorsal horn, using fluorescence retrograde tracing and perforated patch-clamp techniques. TRG neurons were retrogradely labeled with fluorogold (FG). The cell diameter of FG-labeled neurons was small (< 30 mu m). Under the voltage-clamp mode, application of PGE(2) (0.01-10 mu M) concentration-dependently increased the magnitude of the peak tetrodotoxin-resistant sodium current (TTX-R I-Na) and this current was maximal at a concentration of 1 mu M. One micromolar PGE(2) application caused a hyperpolarizing shift of 8.3 mV in the activation curve for TTX-R I-Na. In the current-clamp mode, the PGE(2) (1 mu M) application significantly increased the number of action potentials during the depolarizing step pulses as well as the level of overshoot but had no significant effect on the resting membrane potential. These results suggest that the excitability of small diameter TRG neurons seen after 1 mu M PGE(2) application is involved in an increase in the TTX-R I-Na.