我们已往的实验证明

延髓是针刺镇内脏痛的重要整合部位

内脏神经传入冲动在延髓内有一定投射分布。过去

我们用强电刺激内脏大神经中枢端作为内脏伤害性刺激

由此引起延髓细胞放电、皮肤电、腹肌肌电、动脉血压、瞳孔、胃电等一Experimentes were carried out on 164 rabbits. The transmission of abdominal vagal impulses and the mechanism of inhibitory effect by acupuncture systematically were investigated: 1) Electrical stimulation (single pulse of 20V

0.5ms) of abdominal vagus nerve (AVN) produced two kinds of potential on cervical vagus nerve: the fasl wave (10.4—24.4 M/sec) and the slow wave (0.9—1.7 M/sec)

the later was more stable. 2) In dorsal medulla oblongata the 'M' shaped evoked potentials with long duration (100 ms or so) were recorded. The results suggest that afferents from AVN are mainly transmitted through the small fibres and multi-synaptic connections in Medulla. 3) Out of 301 response units

281 units (93.6％) concentrated in NTS and adjacent regions. This result was also confirmed by injection of Horseradish Peroxides (HRP) in the trunk of AVN. 4) On 24 awake rabbits the VSR were elicited by strong stimulation of AVN. Electroacupuncture (EA) on "Zusanli" points inhibited VSR

an effect lasted over 20 min. This inhibitory effect of EA was reversed partly by Naloxonc (0.5 mg/kg iv) and was attenuated after lesion (DC 0.5 mA

1 min.) of NTS. In conclusion

NTS plays an important role in suppression of VSR by EA (P<0.01).