The descending motor nerve conduction of voluntary swallowing is mainly launched by primary motor cortex (M1). M1 can activate and regulate peripheral nerves (hypoglossal) to control the swallowing. Acupuncture at “Lianquan” acupoint (CV23) has a positive effect against poststroke dysphagia (PSD). In previous work, we have demonstrated that electroacupuncture (EA) could regulate swallowing-related motor neurons and promote swallowing activity in the essential part of central pattern generator (CPG), containing nucleus ambiguus (NA), nucleus of the solitary tract (NTS), and ventrolateral medulla (VLM) under the physiological condition. In the present work, we have investigated the effects of EA on the PSD mice in vivo and sought evidence for PSD improvement by electrophysiology recording and laser speckle contrast imaging (LSCI). Four main conclusions can be drawn from our study: (i) EA may enhance the local field potential in noninfarction area of M1, activate the swallowing-related neurons (pyramidal cells), and increase the motor conduction of noninfarction area in voluntary swallowing; (ii) EA may improve the blood flow in both M1 on the healthy side and deglutition muscles and relieve PSD symptoms; (iii) EA could increase the motor conduction velocity (MCV) in hypoglossal nerve, enhance the EMG of mylohyoid muscle, alleviate the paralysis of swallowing muscles, release the substance P, and restore the ability to drink water; and (iv) EA can boost the functional compensation of M1 in the noninfarction side, strengthen the excitatory of hypoglossal nerve, and be involved in the voluntary swallowing neural control to improve PSD. This research provides a timely and necessary experimental evidence of the motor neural regulation in dysphagia after stroke by acupuncture in clinic.

中文翻译：

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电针参与运动皮层和舌下神经控制改善卒中后吞咽困难小鼠自主吞咽

自主吞咽的下行运动神经传导主要由初级运动皮层（M1）发起。M1可以激活和调节周围神经（舌下神经）来控制吞咽。针灸“连拳”穴位（CV23）对中风后吞咽困难（PSD）有积极作用。在之前的工作中，我们已经证明电针 (EA) 可以调节吞咽相关的运动神经元并促进中枢模式发生器 (CPG) 的重要部分的吞咽活动，包括模糊核 (NA)、孤束核 (NTS) ，以及生理条件下的腹外侧髓质（VLM）。在目前的工作中，我们研究了 EA 对体内PSD 小鼠的影响并通过电生理记录和激光散斑对比成像 (LSCI) 寻找 PSD 改善的证据。我们的研究可以得出四个主要结论：（i）电针可能增强M1非梗塞区的局部场电位，激活吞咽相关神经元（锥体细胞），增加自主吞咽时非梗塞区的运动传导；(ii) EA 可以改善健康侧 M1 和吞咽肌肉的血流量，缓解 PSD 症状；(iii)电针可增加舌下神经运动传导速度(MCV)，增强下颌舌骨肌肌电图，缓解吞咽肌麻痹，释放P物质，恢复饮水能力；(iv) EA可促进非梗死侧M1的功能代偿，增强舌下神经的兴奋性，并参与自主吞咽神经控制以改善 PSD。本研究为临床针灸对脑卒中后吞咽困难的运动神经调节提供了及时、必要的实验依据。