OBJECTIVE:To observe the effect of gastric distention (GD) and acupuncture at three different acupoints on the spontaneous discharge of neurons in the medial vestibular nucleus (MVN),and to clarify the specific function of the MVN in the central integration mechanism underlying acupuncture regulation.METHODS:GD was conducted using a balloon inserted in the stomach cavity,and acupuncture was performed separately at each of three acupoints:Zusanli (ST 36),Quchi (LI 11),and Weishu (BL 21).The effect of acupuncture and GD on the spontaneous discharge of MVN neurons was assessed using a glass microelectrode filled with a sodium acetate electrolyte solution containing 1％ pontamine sky blue;the discharge signals from the neurons were amplified by the microelectrode amplifier and recorded in the Spike2 system.RESULTS:GD and acupuncture significantly affected the spontaneous discharge of MVN neurons.Furthermore,acupuncture at Zusanli (ST 36) and Weishu (BL 21) was significantly more effective at altering the discharge of GD-responsive MVN neurons compared with GD-nonresponsive neurons.CONCLUSION:GD and acupuncture at three different acupoints affected the electrical activity of MVN neurons.The MVN is involved in the central integration mechanism underlying acupuncture regulation of gastric functions.The effects of acupuncture on gastric function may therefore be mediated via these particular MVN neurons.