中文摘要：

首先绘制了蟾蜍脊髓灰质腹角运动神经元池的精确定位图谱，然后分别将浓度为1、0．5、0．1、0．01mol／L的谷氨酸钠溶液及生理盐水（0．65％NaCl，对照组）微量（0．1μL）注射到蟾蜍脊髓灰质腹角运动神经元池，采用BL-420F生物机能实验系统记录腓肠肌收缩曲线，以收缩波的上升相持续时间、最大张力、张力变化速率、下降相持续时间为指标对各组腓肠肌的收缩曲线进行比较。结果：4组实验组腓肠肌的收缩形式是不同程度的强直收缩;各组收缩波的上升相持续时间、最大张力、张力变化速率在一定程度上存在谷氨酸钠量效依赖关系，且1mol／L组腓肠肌强直收缩的张力、张力变化速率显著大于其他各组，这可能是由于谷氨酸钠与运动神经元上谷氨酸受体结合的数量不同造成的。

英文摘要：

A diagram of motor neuron pool of ventral horn of spinal cord gray matter in toad was first delineated. Different concentrations （1, 0.5, 0.1, 0.01 mol/L） of excitatory amino acid L-Glu or physiological saline （0.65% NaCl） were then microinjected into the motor neuron pool in a urethane-anaesthetized toad. The contraction curve of the gastrocnemius was then recorded by the BL-420 Physiological Signal Recording. We took the maximal tension, the duration of rising phase, the velocity of tension variation, and the duration of descending phase as the parameters to study the characteristic of gastroenemius contractility. It was found that the gastrocnemius contractility of all the 4 groups was tetanus but differed in degree, especially the maximal tension, and velocity of tension variation. In contrast to physiological saline, gastrocnemius contracted by the stimulation of L-GIu, and the contraction parameter showed dose-effect relationships except for the duration of descending phase, which was caused by the combination rate of L-Glu and the receptor.