电针“足三里”引起的肌梭传入对大鼠脊髓背角广动力型神经元伤害性反应的影响

Effect of Muscle Spindle Afferent Elicited by Electroacupuncture at "Zusanli" on Nociceptive Response of the Wide Dynamic Range Neurons in Posterior Horn of Spinal Cord in Rats

以大鼠脊髓背角广动力型（ｗｉｄｅ－ｄｙｎａｍｉｃ－ｒａｎｇｅ，ＷＤＲ）神经元伤害性诱发反应为痛指标，观察了电针“足三里”穴引起肌梭传入对其的影响。结果如下：在２２只大鼠上记录到６２例ＷＤＲ神经元，“足三里”穴电针刺激组 ２１例，其中有明显抑制作用的 １５例，占 ７１． ４３％；同样实验条件下，穴区分开 ０．５ｃｍ处给电针刺激组 １４例，结果有明显抑制作用的仅为 ５例，占 ３５．７１％；穴区注射布比卡因破坏肌梭［８］后，施以同样参数的电针刺激组１６例，有明显抑制作用的也仅为５例，占３１．２５％。结果表明，电针“足三里”穴区引起的抑制效应是由于电针刺激引起穴位处的肌梭兴奋，后者的传入信息引起了 ＷＤＲ神经元伤害性反应的抑制效应，从而进一步证实了肌梭的传入具有镇痛作用。

In the present experiment, the late train discharges (c-response) of the wide dynamic range (WDR) neurons evoked by intense electrical stimulation of the skin were taken as nociceptive response. The inhibition produced by muscle spindle afferent elicited by electroacupuncture at "Zusanli" was observed. The results are as follows: 62 WDR neurons were observed in 27 SD rats. 21 were treated by "Zusanli" electroacupuncture, 15 (71. 43% ) of which were inhibited; 14 were treated by electroacupuncture at the point about 0. 5cm lateral to "Zusanli" and avoiding other acupoints nearby. The rate of c-response inhibition is 35. 71 %. The inhibition rate of another group is 31. 25 % which local muscle spindles were destroyed by injecting Bubicaine. The results indicate that the inhibition of c- response induced by electroacupuncture at "Zusanli" point is due to the afferent of local muscle spindles excited by electroacupuncture, and identify the afferent of muscle spindles has analgetic effects.