电针对三叉神经脊束尾侧核会聚神经元镇痛作用的穴位特异性和广泛性

细胞外记录大鼠三叉神经脊束尾侧核会聚神经元对同侧鼻颊部伤害性与非伤害性刺激的反应。用高低两种强度分别电针同属足阳明胃经但属不同神经支配的穴位“下关”和“足三里”。结果表明,低强度电针只有同属三叉神经支配的“下关”穴对伤害性反应有显著抑制作用,而“足三里”无此效应。但高强度电针无论是“下关”还是远节段腓总神经支配的“足三里”穴均产生明显的镇痛效应。表明低强度电针镇痛作用部位的局限性即穴位特异性,而高强度电针镇痛作用范围广泛即镇痛作用的广泛性。这一结果为针刺治疗不同部位痛症的穴位、手法和刺激量的选择提供科学实验的基础。

The Analgesic Extensiveness and Specifity of EA at Different points on Nociceptive Response of Trigeminal Convergent Neurons (TCN)

Our privious work have demonstrated that eletroacupuncture (EA) at acupoints seemed to have no specific effects.The present work is to observe whether the analgesic extensiveness and specificity of EA at points is related to EA intensity and the sites of points.Experiments were carried out on rats anaesthetized with Urathane.The spontaneous discharges and nociceptive responses of convergent neurons on right trigeminal dorsl horn to noxiope stimukition at receptive field (cheek)were recorded extracellarly with glass micro-electrode. EA was applied at ipsilateral "Xiaguan" (on face ) or" Zusanli" (on shank)point with low (2V) and high (18V) intensity. The nociceptive response of TCN could be inhibited by low intensity EA applied at "Xiaguan"but not "Zusanli", shnwing the specificity of points.High intensity EA at either "Xiaguan" or Zusanli" also reduced the responses,showing the analgesic extensiveness of points.We suggest that "the gate of control" mechanism plays an important role in low intensity EA and "DNIC" mechanism does so in high intensity EA.The results suggest that we must pay attention to the manipulation and the intensity of acupuncture in the clinic work