穴位电针对外侧缰核“痛”单位放电的影响

<正> 在针刺镇痛作用研究中,有关边缘前脑的某些结构的作用已引起人们的重视。伤害性刺激可减弱视前区神经元的活动,而穴位电针可加强之。我们已往的工作证明视前区对缰核的放电活动有明显的调节作用,穴位电针可抑制外侧缰核痛兴奋神经元的自发放电。由于缰核对针刺镇痛的重要影响,以及我们在外侧缰核发现还有痛抑制性神经元,针刺对之有何影响,以及它们在针刺镇痛过程中的作用均值得作进一步探讨。

EFFECT OF ACUPUNCTURE POINT ON THE DISCHARGES OF "PAIN" UNITS IN LATERAL HABENULAR NUCLEI (LH)

It had been shown in our previous work that preoptic area might mo- dulate discharges of "pain" units in LH and that the neuronic activities of the preoptic area were also influenced by impulses from acupuncture po- int. So we assumed that the impulses from acupuncture point probably produ- ced the same effect as stimulation of preoptic area on LH. In order to give evidence to this problem, we performed this experiment. Thirty-eight albino rats of both sexes (body weight. 200-320g) were used for this study. The rats were anesthetized with chloralhydrate. The spontaneous firings of LH were recorded by glass microelectrode with co- ordinates: A 4.1 L 0.6 H 4.2. Electrical needling was performed by means of the G6805 type acupunc- ture anesthesia apparatus. The parameters of stimulation were: 100 cycles /sec, intensity 5-7v, 4＇-14＇ in duration. The spontaneous firings of 40 units in LH were recorded. "Pain" stimuli (the clamping of tail or electrostimulation of the sciatic nerves)caused art increase in discharge frequency of 29 units (pain-excitation unit, PE)and a decrease in 11 units (pain-inhibition unit, PI) . The 29 PE in LH all were inhibited by electrostimulation of the preoptic area, and 11 PI all were excited by it for comparing the effect of the pr- eoptic area and acupuncture. Then the effect of acupuncture on LH was observed further. Electrical needling "Zusanli" point might inhibit the discharge of PE in LH(24/29, 82.8%). This inhitory effect lasted for 1＇--6＇. Otherwise effect of the contralateral point was identical with ipsilateral. On the other hand, electrical needling increased freruency of spontaneous firings of PI in LH(7/11, 63.6%)and offset the inhibitcry response to noxious stimuli. From the data presented, it was suggested that the effect of electrical needling "Zusanli" point on two kinds of "pain" unit discharge in LH con- formed with electrostimulation of preoptic area, i.e., it might modulate discharge of "pain" unit in LH. At last, the relationship between this mo- dulatory effect and acupuncture analgesia was discussed.