ABSTRACT
OBJECTIVES: To investigate the effects on the motor function, cortex blood flow perfusion, microglial cells, and the contents of serum inflammatory factors, i.e. interleukin-1ß (IL-1ß), transforming growth factor-ß (TGF-ß), and interleukin-10 (IL-10) after electroacupuncture (EA) preconditioning at "Baihui" (GV20) and "Dazhui" (GV14) in the mice with ischemic stroke, so as to explore the mechanism of EA preconditioning for improving motor function after ischemic stroke. METHODS: C57BL/6 mice were randomly divided into sham-operation group, model group, and EA preconditioning group (EA group), with 15 mice in each group. A photothrombotic method was used to induce the model of unilateral ischemic stroke and motor impairment. The mice in the EA group received EA preconditioning, 20 min each time, once daily for 7 consecutive days before modeling. The motor function of mice was evaluated by the grid-walking test and cylinder test before and after modeling. Laser speckle blood flow video monitoring system was employed to assess the cerebral blood flow perfusion in the primary motor cortex of mice. The contents of IL-1ß, TGF-ß, and IL-10 in the serum were measured by ELISA, and the expressions of microglial cell and M2 subtype cell marker in the primary motor cortex were detected using immunofluorescence staining. RESULTS: After modeling, compared with the sham-operation group, the grid error rate and the dragging rate of the affected limb were increased (P<0.01)ï¼the utilization rate of the affected limb and percentage of the blood perfusion in the affected cortex to healthy side were decreased (P<0.01)ï¼the contents of serum IL-1ß, TGF-ß, and IL-10 were increased (P<0.01, P<0.05)ï¼and the microglia in the primary motor cortex on the affected side showed ameboid, the fluorescence intensity of ionized calcium-binding adapter molecule 1 (IBA1) and CD206 was increased (P<0.01) in the model group. In the EA group, when compared with the model group, the grid error rate and the dragging rate of affected limb were decreased (P<0.01)ï¼the utilization rate of affected limb and the percentage of blood perfusion were increased (P<0.05)ï¼the content of serum IL-1ß was decreased (P<0.01), while the contents of TGF-ß and IL-10 were increased (P<0.01)ï¼and the microglia in the primary motor cortex on the affected side got more round and were distributed more densely, the fluorescence intensity of IBA1 and CD206 was increased (P<0.01). CONCLUSIONS: Electroacupuncture preconditioning at "GV20" and "GV14" can up-regulate the expression of microglial cells, especially the M2 subtype cell marker, and increase the contents of the anti-inflammatory factors and decrease that of the pro-inflammatory factors in the serum, thereby alleviate the inflammatory reaction.
Subject(s)
Electroacupuncture , Ischemic Stroke , Mice , Animals , Microglia , Interleukin-10/genetics , Electroacupuncture/methods , Mice, Inbred C57BL , Transforming Growth Factor betaABSTRACT
As a traditional medical therapy, stimulation at the Lianquan (CV23) acupoint, located at the depression superior to the hyoid bone, has been shown to be beneficial in dysphagia. However, little is known about the neurological mechanism by which this peripheral stimulation approach treats for dysphagia. Here, we first identified a cluster of excitatory neurons in layer 5 (L5) of the primary motor cortex (M1) that can regulate swallowing function in male mice by modulating mylohyoid activity. Moreover, we found that focal ischemia in the M1 mimicked the post-stroke dysphagia (PSD) pathology, as indicated by impaired water consumption and electromyographic responses in the mylohyoid. This dysfunction could be rescued by electroacupuncture (EA) stimulation at the CV23 acupoint (EA-CV23) in a manner dependent on the excitatory neurons in the contralateral M1 L5. Furthermore, neuronal activation in both the parabrachial nuclei (PBN) and nucleus tractus solitarii (NTS), which was modulated by the M1, was required for the ability of EA-CV23 treatment to improve swallowing function in male PSD model mice. Together, these results uncover the importance of the M1-PBN-NTS neural circuit in driving the protective effect of EA-CV23 against swallowing dysfunction and thus reveal a potential strategy for dysphagia intervention.
Subject(s)
Deglutition Disorders , Electroacupuncture , Motor Cortex , Stroke , Male , Mice , Animals , Solitary Nucleus , Deglutition/physiology , Deglutition Disorders/etiology , Deglutition Disorders/therapy , Electroacupuncture/methods , Stroke/complications , Stroke/therapyABSTRACT
Acupuncture at acupoints Baihui (GV20) and Dazhui (GV14) has been shown to promote functional recovery after stroke. However, the contribution of the contralateral primary sensory cortex (S1) to recovery remains unclear. In this study, unilateral local ischemic infarction of the primary motor cortex (M1) was induced by photothrombosis in a mouse model. Electroacupuncture (EA) was subsequently performed at acupoints GV20 and GV14 and neuronal activity and functional connectivity of contralateral S1 and M1 were detected using in vivo and in vitro electrophysiological recording techniques. Our results showed that blood perfusion and neuronal interaction between contralateral M1 and S1 is impaired after unilateral M1 infarction. Intrinsic neuronal excitability and activity were also disturbed, which was rescued by EA. Furthermore, the effectiveness of EA treatment was inhibited after virus-mediated neuronal ablation of the contralateral S1. We conclude that neuronal activity of the contralateral S1 is important for EA-mediated recovery after focal M1 infarction. Our study provides insight into how the S1-M1 circuit might be involved in the mechanism of EA treatment of unilateral cerebral infarction. The animal experiments were approved by the Committee for Care and Use of Research Animals of Guangzhou University of Chinese Medicine (approval No. 20200407009) April 7, 2020.