Zhen Ci Yan Jiu. 1989 ; 14(4): 410-3.

[The effect of electro-acupuncture of "neiguan" acupoint on cortical potential evoked by stimulating C-fibers of splanchnic nerve]

Zhang JM, Guo LN, Chen PX.

In this paper the averaged cortical evoked potential (C-CEP) induced by stimulating the C-fibers of the splanchnic nerve was used as an index of visceral pain to further study the effects of acupuncture and morphine on it. Experiments were carried out on 35 cats anesthetized with chloralose and immobilized with flaxedil. The splanchnic nerve was stimulated with electric pulses of varied strength and blocked by a galvanic current so as to cause A- or C-fibers input selectively. The cortical evoked potential was recorded on the contralateral post-sigmoid gyrus and averaged by TQ-19 Medical Data Processor. The compound action potential of splanchnic nerve was monitored. "Neiguan" acupoint was stimulated with electric pulses (0.1ms, 4v and 5Hz). The results were as follows: 1) when "Neiguan" acupoint, was excited with the electric pulses, C-CEP and the late component of A-CEP which was evoked by stimulating A-fibers of splanchnic nerve were obviously reduced in amplitudes. It was suggested that electro-acupuncture (EA) of "Neiguan" acupoint could inhibit visceral pain (the slow and fast pain). 2. After intravenous injection of morphine, the amplitudes of C-CEP and the late component of A-CEP were depressed significantly, indicating that C-CEP might reflect the visceral slow pain and the late component of A-CEP reflect the fast pain. 3. Naloxone could block partially the inhibitory effect of EA of "Neiguan" acupoint on C-CEP, suggesting that the inhibition of EA might be associated with the release of endogenous opiate like substances.