Shen E, Ma W H, Lan C
Sci Sin. 1978 Sep-Oct;21(5):677-85.
The possible involvement of descending inhibition in the effect of acupuncture on the transmission of visceral afferent impulses has been investigated. Averaged splanchnically evoked potentials were recorded in the orbital cortex of the unanesthetized immobilized cat. The evoked orbital potentials could be inhibited by electroacupuncture. Section of the descending inhibitory pathway which is known to be located in the dorsolateral funiculi of the spinal cord produced marked diminution of the acupuncture inhibitory effect on the evoked cortical potentials with needles either inserted in the hindlimb or in the forelimb. Since the afferent impulses from the forelimb entered the cord above the level of section (T3-4), the ascending pathway for acupuncture signals to the supraspinal structure was thus left intact. Destruction of the pontobulbar reticular formation including mainly the nucleus raphe magnus produced the same diminution of the acupuncture effect. The results indicate that the ascending visceral afferent impulses are blocked at the level of the spinal cord by the acupuncture-induced descending impulses from the supraspinal center, probably the nucleus raphe magnus.
针刺对内脏传入冲动传导的影响中下行抑制可能参与的情况已被研究。在未麻醉的固定猫的眶皮质记录平均内脏诱发电位。诱发性眶电位可被电针抑制。已知位于脊髓背外侧索的下行抑制通路切断后，无论是将针插入后肢还是前肢，针刺对诱发性皮质电位的抑制作用都明显减弱。由于来自前肢的传入冲动在切断水平（T3 - 4）以上进入脊髓，因此针刺信号向上行至脊髓上结构的通路保持完整。主要包括中缝大核在内的脑桥延髓网状结构破坏后，针刺效应同样减弱。结果表明，脊髓上中枢（可能是中缝大核）针刺诱导的下行冲动在脊髓水平阻断了上行内脏传入冲动。
