Electroacupuncture ameliorates gastrointestinal dysfunction by modulating DMV cholinergic efferent signals to drive the vagus nerve in p-MCAO rats

Abstract

BackgroundThe use of proton pump inhibitors in the acute phase of cerebral infarction may lead to adverse long-term outcomes, this study aims to explore the potential of electroacupuncture (EA) in replacing omeprazole in exerting post-stroke gastrointestinal protection. MethodsA permanent middle cerebral artery infarction model was established using the modified Longa thread occlusion technique. Gastrointestinal motility, gastrointestinal mucosal damage, cerebral infarct volume, and alterations in choline acetyltransferase (ChAT)-positive neurons within the dorsal motor nucleus of the vagus nerve (DMV) were assessed after 7 days of EA at Zusanli (ST36) or omeprazole intervention. To evaluate the role of the vagal nerve in mitigating post-stroke gastrointestinal dysfunction, we employed subdiaphragmatic vagotomy and the ChAT-specific inhibitor α-NETA. Additionally, we utilized methyllycaconitine (MLA), a selective inhibitor of the α7-type nicotinic acetylcholine receptor (α7nAChR), and PNU282987, an agonist, to identify the target of EA. ResultsEA restored ChAT neurons lost in the DMV, activated the vagus nerve and conferred cerebroprotection while ameliorating gastrointestinal mucosal injury and gastrointestinal motility disorders. In addition, following the administration of the α7nAChR antagonist, the attenuation of gastric mucosal injury and inflammatory factors induced by EA was hindered, although gastrointestinal motility still exhibited improvement. ConclusionEA at ST36 promotes the restoration of cholinergic signaling in the DMV of stroke-afflicted rats, and its excitation of the vagal nerve inhibits gastrointestinal inflammation after stroke via α7nAChR, while improvement in gastrointestinal motility could be mediated by other acetylcholine receptors.