NMDA Receptors of Gastric-Projecting Neurons in the Dorsal Motor Nucleus of the Vagus Mediate the Regulation of Gastric Emptying by EA at Weishu (BL21)

Abstract

A large number of studies have been conducted to explore the efficacy of electroacupuncture (EA) for the treatment of gastrointestinal motility. While several lines of evidence addressed the basic mechanism of EA on gastrointestinal motility regarding effects of limb and abdomen points, the mechanism for effects of the back points on gastric motility still remains unclear. Here we report that the NMDA receptor (NMDAR) antagonist kynurenic acid inhibited the gastric emptying increase induced by high-intensity EA at BL21 and agonist NMDA enhanced the effect of the same treatment. EA at BL21 enhanced NMDAR, but not AMPA receptor (AMPAR) component of miniature excitatory postsynaptic current (mEPSC) in gastric-projecting neurons of the dorsal motor nucleus of the vagus (DMV). In sum, our data demonstrate an important role of NMDAR-mediated synaptic transmission of gastric-projecting DMV neurons in mediating EA at BL21-induced enhancement of gastric emptying.

The Neural Mechanism by Which the Dorsal Vagal Complex Mediates the Regulation of the Gastric Motility by Weishu (RN12) and Zhongwan (BL21) Stimulation

“…We discovered that the combined EA stimulation of gastric Shu and Mu points has synergistic effects. It is worth noting that, although most cases showed an upregulation of gastric motility by EA at BL21 and RN12 [9], in some cases EA at these points failed to accelerate gastric motility, or even inhibited gastric motility, which is similar to previous reports [10]. …”

Treatment of Diabetic Gastroparesis by Complementary and Alternative Medicines

“…Previous reports have demonstrated that complementary therapy could significantly improve epigastric symptoms and gastric emptying in gastroparesis [ 19 , 25 , 26 ]. Animal experiments revealed that acupuncture could modulate gastric motility via the autonomic nervous system in normal and diabetic model rats [ 27 , 28 , 29 ]. Various complementary therapeutics exhibited possibilities for the treatment of diabetic gastroparesis.…”

The Neural Pathway of Reflex Regulation of Electroacupuncture at Orofacial Acupoints on Gastric Functions in Rats

“…Anatomical evidence demonstrates that somatic afferents induced by EA at ST-36 is conveyed to the NTS and acts on the DMV, which promote gastric motility [23]. Moreover, NMDA receptors of gastric-projecting neurons in the DMV are involved in the regulation of EA at BL21 on gastric emptying in rats [25]. Our previous works also show that EA at ST36 enhanced the GMI and simultaneously inhibited release of Substance P in the DVC, which is abolished by transaction of vagus nerves [2].…”