在本研究室“内脏神经传入冲动诱发猫丘脑后核(PO)单位放电的观察”一文中

发现刺激内脏大神经于丘脑后核中可看到不同潜伏期的2～3簇放电成分。本文除用相同方法研究PO细胞放电

特别是痛放电外

还研究了刺激外周神经(腓总神经及隐神经)时对单位放电的影响

以期了解外周神经中不同机能纤维兴奋对PO细胞痛放电的作用

为研究体躯感觉与内脏感觉的整合作用和针刺镇痛提供理论基础。方法实验用2.0～3.5公斤体重的描30A previous paper of our laboratory reported the unit discharges of PO nucleus evoked by stimulating the splanchnic nerve. These discharges showed 2-3 kinds of clusters with different latent periods. In this article we specially studied the feature of such neuron dischar- ges with the same method used previously. As we stimulated the splanchnic nerve with weak stimulus

only one response(the 1st response)could be caused. Its latent period was shorter (43.4±8.9 msec). As the stimulus became stronger the 2nd late response would be elicited. Its latent period was 257±53 msec. In addition to causing evoked discharges with stimulating splanchnic nerve

the spontaneous discharges also increased. The phenomenon of in- creasing frequency still continued after the stimulating had been stopped. After the intravenous injection of Dolantin (5mg/kg)

the evoked di- scharges of the neuron resulting from splanchnic nerve disappeared. The 2nd response disappeared first and then the 1st response

but after a period of time the two components recovered in a reverse order. The evoked unit discharges of the PO nucleus were inhibited obviously by stimulating the peripheral somatic nerves(common peroneal nerve and saphenous nerve). When the stimulus acting to the peripheral somatic nerve was weak

the evoked unit discharges of the neuron were not inhibi- ted or inhibited slightly. The stronger the stimulus acting on the periph- eral somatic nerve

the more distinct would be the inhibition of the evoked unit discharges. We suppose that the unit discharges in PO nucleus evoked by stimula- ting splanchnic nerve has the characteristic of pain response The inhibition resulting from the stimulation of the peripheral somatic nerve might be the basis of acupuncture analgesia.