Y ANG Zhaokun, W ANG Xiaoyu, HE Wei, SHI Hong, SU Yangshuai, HU Ling, JINGXianghong

(Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing ,100700)

Abstract: Objective: The aim of this study was to  synchronous observe the regulative effect of  electroacupuncture  (EA)  at  ST36  and  CV12  on  gastrointestinal  motility  and  the  firing  rate  of gastric  related neurons in  the  NTS and DMV after intragastric administration of acid. Methods: 36 rats were randomly divided into three groups: intragastric acid administration group, EA ST36 group and EA CV12 group. Neuronal spikes in the rat brainstem  after intragastric administration of HCl(0.5  mol/L) was recorded by  electrode, which  was acutely implanted to span the the nucleus of  solitary  tract  (NTS)  and  dorsal  motor  nucleus  of  vagus  (DMV).  EGG  was  continuously monitored and recorded synchronously by the bipolar electrode, which was in the muscle layer of gastric Antrum.  Results:  Intragastric  administration  of  0.5M/L  HCL  led  to  a  rapid  increase  in integral of gastric slow wave (GSW) and firing rates of excitatory neurons in the NTS, which was significant at 90 seconds and remained elevated for 45mins（P＜0.01）. Acid administration led to a slow decline in  firing rates of inhibitory  neurons in  the  DMV that was significant at 4  mins and continued to decline for 1 hour（P＜0.01）.  In the time-window from 8 mins to 30  mins after intragastric acid administration, EA at ST36 and CV12 elicited inhibitory effects on severe gastric motility. There was no difference between EA  at  ST36 and CV12（P＞0.05）.  EA at ST36 and CV12 elicited inhibitory effects on excitatory neurons in NTS with intragastric acid administration, and the inhibition rate induced by EA ST36 significantly increased in comparison with EA CV12（P＜0.05）. EA at ST36 and CV12 did not cause significant changes in firing rates of inhibitory neurons in DMV（P＞0.05）.  Conclusion:  In conclusion, EA at ST36 and CV12 regulated gastric nociceptive visceral afferent in NTS, rather than visceral motor efferent in DMV in gastric acid challenge. The difference between the two points possibly connected with different never  afferent. EA at ST36 directly contacted with NTS through the vagus visceral afferent, and EA at CV12 through sympathetic splanchnic afferent contacted with spinal dorsal horn.

Key words:  Electroacupuncture, Acupoint, Gastric Acid  Challenge，Visceral  Sensory , Visceral Motor