Excitatory neurons in paraventricular hypothalamus contributed to the mechanism underlying acupuncture regulating the swallowing function

Mapping research trends regarding the mechanism of dysphagia from 1993 to 2023: a bibliometrics study and visualization analysis

As a common consequence of various neurogenic disorders, dysphagia has a significant impact on the quality of life for patients. To promote the development the field of swallowing, it will be helpful to clarify the pathological and therapeutic mechanisms of dysphagia. Through visual analysis of related papers from 1993 to 2023 in the Web of Science Core Collection (WoSCC) database, the research status and development trend of the pathogenesis of dysphagia were discussed. The co-occurrence study was finished using CiteSpace 6.2 R4 software, including keywords, countries, institutions, and authors. Finally, 1,184 studies satisfied the inclusion requirements. The findings of the visualization analysis suggested that aspiration and gastroesophageal reflux disease would be the areas of greatest interest for researchers studying the mechanism of dysphagia. As for the latest occurred research trends, fMRI, signals and machine learning emerging into the field of view of researchers. Based on an analysis of country co-occurrence, United States, Japan and China rank the top three, in terms of the number of publications on dysphagia. University System of Ohio is the organization that has published the most amount of articles regarding the mechanism of dysphagia. Other highly published schools in the top three include State University System of Florida and Northwestern University. For the prolific authors, German, Rebecca Z published the most articles at present, whose own research team working closely together. Several closely cooperating research teams have been formed at present, including the teams centered around German, Rebecca Z, Warnecke, Tobias and Hamdy Shaheen. This study intuitively analyzed the current research status of the mechanism of dysphagia, provided researchers with research hotspots in this field.

Neural circuit mechanisms of acupuncture effect: where are we now?

Recently, there has been increasing attention on the impact of acupuncture on the dysregulated neural circuits in different disease. This has led to new understandings of how acupuncture works. This review presents a comprehensive analysis of research that have examined the impact of acupuncture on abnormal neural circuits associated with pain, anxiety, Parkinson's disease, addiction disorders, cognitive problems, and gastrointestinal disorders. These studies have shown that acupuncture's therapeutic effects are mediated by specific brain areas and neurons involved in neural circuit mechanisms, emphasising its wide-ranging influence. The positive impacts of acupuncture can be ascribed to its ability to modify the functioning of neurocircuits in various physiological conditions. Nevertheless, contemporary studies on acupuncture neural circuits frequently overlook the comprehensive circuit mechanism including the periphery, central nervous system, and target organ. Additionally, the scope of diseases studied is restricted. Future study should focus on broadening the range of diseases studied and exploring the neural circuit mechanisms of these diseases in depth in order to enhance our understanding of acupuncture's neurobiological impacts.

Role of TRPV1 in electroacupuncture-mediated signal to the primary sensory cortex during regulation of the swallowing function

AIMS

Electroacupuncture (EA) at the Lianquan (CV23) could alleviate swallowing dysfunction. However, current knowledge of its neural modulation focused on the brain, with little evidence from the periphery. Transient receptor potential channel vanilloid subfamily 1 (TRPV1) is an ion channel predominantly expressed in sensory neurons, and acupuncture can trigger calcium ion (Ca2+ ) wave propagation through active TRPV1 to deliver signals. The present study aimed to investigate whether TRPV1 mediated the signal of EA to the primary sensory cortex (S1) during regulation of swallowing function.

METHODS

Blood perfusion was evaluated by laser speckle contrast imaging (LSCI), and neuronal activity was evaluated by fiber calcium recording and c-Fos staining. The expression of TRPV1 was detected by RNA-seq analysis, immunofluorescence, and ELISA. In addition, the swallowing function was assessed by in vivo EMG recording and water consumption test.

RESULTS

EA treatment potentiated blood perfusion and neuronal activity in the S1, and this potentiation was absent after injecting lidocaine near CV23. TRPV1 near CV23 was upregulated by EA-CV23. The blood perfusion at CV23 was decreased in the TRPV1 hypofunction mice, while the blood perfusion and the neuronal activity of the S1 showed no obvious change. These findings were also present in post-stroke dysphagia (PSD) mice.

CONCLUSION

The TRPV1 at CV23 after EA treatment might play a key role in mediating local blood perfusion but was not involved in transferring EA signals to the central nervous system (CNS). These findings collectively suggested that TRPV1 may be one of the important regulators involved in the mechanism of EA treatment for improving swallowing function in PSD.

Systematic review and meta-analysis of the efficacy and safety of electroacupuncture for poststroke dysphagia

Introduction

Optimal treatment strategies for post-stroke dysphagia (PSD) remain to be explored. Electroacupuncture (EA) has attracted widespread attention due to its simplicity, cheapness, and safety. However, the efficacy of EA in the treatment of PSD lacks high-level evidence-based medical support. This study aimed to systematically evaluate the clinical value of EA in the treatment of PSD.

Methods

A total of seven databases were searched for relevant literature. All randomized controlled trials (RCTs) on EA alone or EA combined with other interventions for the treatment of PSD were assessed using the modified Jadad scale. The studies with a score of ≥4 were included. The quality of the included studies was then assessed using the Cochrane Collaboration's tool. The meta-analysis was performed using Rev. Man 5.3 software.

Results

Twelve studies involving 1,358 patients were included in the meta-analysis. Meta-analysis results showed that the EA group was superior to the control group in terms of clinical response rate (OR = 2.63, 95% CI = 1.97 to 3.53) and videofluoroscopic swallowing study (VFSS) score (MD = 0.73, 95% CI = 0.29 to 1.16). There was no significant difference between the two groups in the standardized swallowing assessment (SSA) score (MD = -3.11, 95% CI = -6.45 to 0.23), Rosenbek penetration-aspiration scale (PAS) score (MD = -0.68, 95% CI = -2.78 to 1.41), Swallowing Quality of Life (SWAL-QOL) score (MD = 13.24, 95% CI = -7.74 to 34.21), or incidence of adverse events (OR = 1.58, 95% CI = 0.73 to 3.38).

Conclusion

This study shows that EA combined with conventional treatment or other interventions can significantly improve the clinical response rate and VFSS score in patients with PSD without increasing adverse reactions.Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=396840.

The Role of Perineuronal Nets in the Contralateral Hemisphere in the Electroacupuncture-Mediated Rehabilitation of Poststroke Dysphagia Mice

Acupuncture at Lianquan (CV23) acupoint has been shown to improve swallowing function in poststroke dysphagia (PSD). This improvement is supposed to be associated with the regulation of neuronal activity in the contralateral primary motor cortex (M1), while the underlying mechanism still needs to be elucidated. Perineuronal nets (PNNs) are well-known to be involved in the regulation of neuronal activity. Thus, we here aimed to detect the role of PNNs in the contralateral M1 hemisphere in the electroacupuncture (EA)-mediated effect in male mice. The results were obtained from a combination of methods, including in vitro slice electrophysiological recording, in vivo electrophysiological recording, and immunofluorescent staining in male mice. These results showed a decrease of the excitatory postsynaptic currents (sEPSCs) and no alteration of the inhibitory postsynaptic currents (sIPSCs) in the GABAergic neurons and the tonic inhibition in the excitatory neurons in the contralateral M1 after stroke induction, and EA recovered the impaired sEPSCs in the GABAergic neurons. We further found that the effect of EA-induced increase of c-Fos expression, enhancement of spike firing, potentiation of sEPSCs in the excitatory neurons, and improvement of swallowing function were all blocked by the removal of PNNs in the contralateral M1. In conclusion, the PNNs in the contralateral M1 was suggested to be participated in stroke pathogenesis and might be associated with the EA-mediated swallowing function rehabilitation of PSD in male mice. Our study provides insight into how PNNs might be involved in the mechanism of EA treatment for stroke rehabilitation.

Acupuncture for swallowing disorder after recovery from COVID-19: A protocol for systematic review and meta analysis

BACKGROUND

Swallowing disorder is a common sequela after recovery from COVID-19. Acupuncture is an important traditional therapy for treating swallowing disorder. However, the efficacy of acupuncture for swallowing disorder after recovery from COVID-19 lacks evidence-based medicine.

METHODS

All randomized controlled trials of acupuncture for swallowing disorder after recovery from COVID-19 will be retrieved and collected from December 2019 to November 2022 with no language restrictions. PubMed, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure Database, Chinese Biomedical Database, Chinese Science and Technology Journal Database (VIP), and the Wanfang Database will be searched. Two researchers will independently select studies, extract data, and evaluate study quality. The Cochrane risk of bias tool for randomized trials will be used to assess the risk of bias in the included studies. Statistical analyses will be performed using Review Manager version 5.3.

RESULTS

This study will provide a high-quality and convincing assessment of the efficacy and safety of acupuncture for swallowing disorder after recovery from COVID-19 and will be published in peer-reviewed journals.

CONCLUSION

Our findings will provide a reference for future clinical decisions and guidance development.

Electroacupuncture improves swallowing function in a post-stroke dysphagia mouse model by activating the motor cortex inputs to the nucleus tractus solitarii through the parabrachial nuclei

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.