我们以往的工作证明电针“足三里”穴的信息在中枢神经内是循躯体感觉通路而传递的;恶心、呕吐反射的传入冲动主要由迷走神经的传入纤维传至延髓的孤束核下段—连合核

然后上行至脑桥上部的结合臂旁核。电针“足三里”穴可以在连合核和The experiments were performed by

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H-2-deoxyglucose autoradiography to investigate the effects of naloxone on the trasmission of acupuncture messages involved in the inhibitory action upon the visceral traction reactions by pulling stomach.In 8 rats

after the naloxone(125μg/0.2mL

iv)was administrated

The results showed:(1) The optical density of the left dorsal horn of lower lumbar spinal cord distinctly increased due to acupuncture at ipsilateral “Zusanli”acupoint(n=8).(2)When the raise of the optical density of ipsilateral nucleus gracilis as a result of acupuncture was depressed by nalo- xone(n=5)

the optical density of commissural nucleus was elevated by pulling stomach.(3)On the contrary

when the raise of the optical density of nucleus gracilis was not depressed(n=3)

the optical density of the later nucleus was not elevated by pulling stomach.(4)The naloxone also depressed the raise of the optical density of contralateral posterolateral ventral nucleus of thalamus induced by acupuncture at“Zusanli”acupoint(n=8)and the raise of the optical density of parabrachial nucleus induced by pulling stomach (n=7). It suggested:(1)The transmission of acupuncture messages from“Zusanli” acupoint to dorsal horn was not influenced

but it from dorsal horn to nucleus gracilis gracilis was blocked by naloxone.It means that the messages of acupuncture at“Zusanli”acupoint via non-enkephanergic primay sensory neurons transmit to dorsal horn of spinal cord.Then

they go up to the nucleus graciliso

In this transmitting process

the enkephaline seem to be main participant.(2)The contrary changes of the optical density between commi- sural nucleus and nucleus gracilis illustrated that the acupuncture messages which transmit from dorsal horn to nucleus gracilis might play an important role in the inhibitory effect of acupuncture on the visceral traction reactions. (3)The enkephaline might also participate in the transmission of acupuncture messages from nucleus gracilis to contralateral posterolateral ventral nucleus of thalamus

and in the transmission of the inflow of the visceral traction reactions induced by pulling stomach from commisural nucleus to parabrachial nucleus.