title: NMDA Receptor-Dependent Synaptic Activity in Dorsal Motor Nucleus of Vagus Mediates the Enhancement of Gastric Motility by Stimulating ST36.
abstract: Previous studies have demonstrated the efficacy of electroacupuncture at ST36 for patients with gastrointestinal motility disorders. While several lines of evidence suggest that the effect may involve vagal reflex, the precise molecular mechanism underlying this process still remains unclear. Here we report that the intragastric pressure increase induced by low frequency electric stimulation at ST36 was blocked by AP-5, an antagonist of N-methyl-D-aspartate receptors (NMDARs). Indeed, stimulating ST36 enhanced NMDAR-mediated, but not 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic-acid-(AMPA-) receptor-(AMPAR-) mediated synaptic transmission in gastric-projecting neurons of the dorsal motor nucleus of the vagus (DMV). We also identified that suppression of presynaptic μ-opioid receptors may contribute to upregulation of NMDAR-mediated synaptic transmission induced by electroacupuncture at ST36. Furthermore, we determined that the glutamate-receptor-2a-(NR2A-) containing NMDARs are essential for NMDAR-mediated enhancement of gastric motility caused by stimulating ST36. Taken together, our results reveal an important role of NMDA receptors in mediating enhancement of gastric motility induced by stimulating ST36.
authors.affiliation: Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, 16 Nanxiaojie Street, Dongzhimennei, Beijing 100700, China.
authors.forename: Xinyan
authors.initials: X
authors.lastname: Gao
authors.forename: Yongfa
authors.initials: Y
authors.lastname: Qiao
authors.forename: Baohui
authors.initials: B
authors.lastname: Jia
authors.forename: Xianghong
authors.initials: X
authors.lastname: Jing
authors.forename: Bin
authors.initials: B
authors.lastname: Cheng
authors.forename: Lei
authors.initials: L
authors.lastname: Wen
authors.forename: Qiwen
authors.initials: Q
authors.lastname: Tan
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.forename: Bing
authors.initials: B
authors.lastname: Zhu
authors.forename: Haifa
authors.initials: H
authors.lastname: Qiao