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藜芦碱和乌头碱在受损背根节神经元诱发不同的放电模式

段建红, 邢俊玲, 杨晶, 胡三觉

第四军医大学神经科学研究所.陕西,西安 710032

摘要

为了研究钠通道失活门阻断后受损背根节神经元放电模式的变化特征,在大鼠背根节慢性压迫模型上采用单纤维技术记录A类神经元的自发放电。藜芦碱和乌头碱是钠通道失活门的抑制剂,但二者作用于不同的位点,前者结合于D2--S6,后者结合于D3--S6。作者比较了这两种试剂引发的放电模式。结果发现,在同一神经元,藜芦碱(1.5---5.0 #mu#mol/L)可以引起放电峰峰间期的慢波振荡,即峰峰间期由大逐渐减小,然后又逐渐增大,形成重复的振荡波形,每个振荡持续约数十秒至数分钟;而乌头碱(10---200 #mu#mol/L)则引起强直性放电,即峰峰间期逐渐减小,然后维持在一个稳定的水平。这两种不同的放电模式不因背景放电或试剂浓度的不同而发生明显的改变。实验结果表明,藜芦碱和乌头碱在受损的背根节神经元可以引发不同的放电模式,这可能与它们结合于钠通道上不同位点的抑制作用有关。

关键词： 背根节; 放电模式; 藜芦碱; 乌头碱; 钠通道

Different firing patterns induced by veratridine and aconitine in injured dorsal root ganglion neurons

Duan Jianhong, Xing Junling, Yang Jing, Hu Sanjue

Institute of Neuroscience,The Fourth Military Medical University.Xi'an 710032,Shaanxi

Abstract

Ectopic spontaneous activity originated from the injured dorsal root ganglion (DRG) neurons in rats was recorded through single dorsal root fiber. The firing patterns induced by veratridine and aconitine, inhibitors of inactivation gate of sodium channel operating on different binding sites, were compared. In the same neuron, veratridine (1.5--5.0 #mu#mol/L) caused slow wave oscillations of interspike intervals (ISIs), while aconitine (10--200 #mu#mol/L) caused tonic firing. Moreover, even if the background firing patterns were various and the reagent concentrations used were different, veratridine and aconitine still induced slow wave oscillations and tonic firing patterns, respectively. The results suggest that veratridine and aconitine induce different firing patterns in injured DRG neurons, which may relate to their inhibitory effects on different binding sites of the sodium channel.

Key words: dorsal root ganglion;firing patterns;veratridine;aconitine;sodium channels

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引用本文：

段建红, 邢俊玲, 杨晶, 胡三觉. 藜芦碱和乌头碱在受损背根节神经元诱发不同的放电模式[J]. 生理学报 2005; 57 (2): .

Duan Jianhong, Xing Junling, Yang Jing, Hu Sanjue. Different firing patterns induced by veratridine and aconitine in injured dorsal root ganglion neurons. Acta Physiol Sin 2005; 57 (2): (in Chinese with English abstract).