细纤维活动引起的大鼠脊髓背表面电位

Spinal dorsum potential evoked by activation of the fine fibers in rat

以浅麻醉和麻痹大鼠为对象,利用计算机叠加技术观察了对脖肠神经施加不同强度的电刺激所诱发的脊髓背表面电位(CDP)的波形;延髓网状巨细胞核(NGC)对CDP的影响。实验发现,大鼠腓肠神经诱发的CDP由N_1、N_2、P_1、N_3、P_2、N_4波组成。在同侧NGC微量注射谷氨酸钠后,A_β纤维引起的N_1波无显著性改变,A_β和A_δ纤维引起的P_1波以及A_δ和C纤维引起的N_3波轻微减小,C类纤难引起的P_2和N_4波明显减小。结果提示:NGC对由细纤维诱发的CDP成分有抑制作用。

The present study was performed with averaging technique on light chloral hydrate-anesthetized and immobilized rat. The waveform of the cord dorsum potential (CDP) evoked by the stimulation of the sural nerve with graded current intensity was recorded with the computer averaging technique, and the observation of the effects of the nucleus reticularis gigantocellularis (NGC) on CDP were made. It was found that the rat CDP evoked by the stimulation of the sural nerve is composed of N_1, N_2, P_1, N_3, P_2 and N_4 waves. Microinjection of L-glutamate sodium into bilateral NGC reduced the amplitudes of P_1, N_3, P_2 and N_4-waves,but not N_1-waves, and the reduction of the amplitudes of P_2 and N_4 waves was more prominent. The results indicate that NGC exerts an inhibitory influence on the CDP-forms evoked by the fine fibers of the sural nerve.