[Mechanism of melatonin-mediated antihyperglycemic effect of transcutaneous auricular vagus nerve stimulation].

OBJECTIVE: To observe the effects of transcutaneous auricular vagus nerve stimulation （taVNS） on plasma melatonin （MLT） content and insulin receptor expression in the liver, the skeletal muscles, and the pancreas of Zucker diabetic fatty （ZDF） rats, so as to explore the hypoglycemic mechanism of taVNS. METHODS: Thirty male ZDF rats were randomly divided into model group, taVNS group and sham-taVNS group, with 10 rats in each group； besides, 10 male Zucker lean rats of the same strain were collected for the blank control group. ZDF rats were fed with high-fat diet to induce type 2 diabetes mellitus （T2DM） rat model. In the taVNS group, HANS-100A electroacupuncture instrument was used to stimulate the cavum conchae of both sides. The stimulation sites of rats in the sham-taVNS were the same as the taVNS group, but without electricity delivered. The above interventions were performed 30 min each time, once daily, lasting for 6 weeks. Fasting blood glucose （FBG） was measured weekly in each group, the plasma metatonin （MLT） content was detected by ELISA, and the insulin receptor expression level in the liver, the skeletal muscle and the pancreas was determined by Western blot. RESULTS: Compared with the blank control group, the level of FBG of rats were increased （P<0.01）, the plasma MLT content was decreased （P<0.01） and the insulin receptor expression level in the pancreatic tissue was decreased （P<0.01） in the model group. In the taVNS gruop, FBG was decreased （P<0.05, P<0.01）, the plasma MLT content was increased （P<0.01）, and the insulin receptor expression level in the liver, the skeletal muscle and the pancreas was increased （P<0.05, P<0.01, P<0.001） when compared with the model group. Compared with the taVNS group, FBG was increased （P<0.05, P<0.01）, the plasma MLT content was decreased （P<0.01）, and the expression level of insulin receptors in the skeletal muscle and the pancreas was decreased （P<0.01, P<0.001） in the sham-taVNS group. CONCLUSION: The taVNS can improve the insulin resistance and ultimately obtain the antihyperglycemic effect through regulating MLT concentration.

Anti-neuroinflammation effects of transcutaneous auricular vagus nerve stimulation against depression-like behaviors via hypothalamic α7nAchR/JAK2/STAT3/NF-κB pathway in rats exposed to chronic unpredictable mild stress.

BACKGROUND: Transcutaneous auricular vagus nerve stimulation (taVNS) is a vital neuromodulation for the treatment of depression, but its antidepressant molecular mechanism is unclear. The α7 nicotinic acetylcholine receptor (α7nAchR) is a key mediator of the vagus nerve that mediates its anti-inflammatory efficacy. Here, we investigated whether the antidepressant effect of taVNS in chronic unpredicted mild stress (CUMS)-exposed rats works through the α7nAchR/JAK2/STAT3/NF-κB pathway. METHODS: The depression model was established by CUMS for continuous 6 weeks in rats. From the 4th week of the experiment, CUMS-exposed rats were subjected to taVNS for 3 weeks. To clarify the role of α7nAchR in the antidepressant effect of taVNS, we used α7nAchR-/- gene knockout rats. The sucrose preference test (SPT), open field test (OFT), and forced swimming test (FST) were used to evaluate depression-like behaviors of rats. Immunofluorescent staining was used to observe the morphology of microglia in the hypothalamus. Western blot was used to examine the protein expression of α7nAchR, p-JAK2, p-STAT3, IL-1ß, NF-κB p65, and p-NF-κB p65 in the hypothalamus. RESULTS: Depression-like behaviors in CUMS-exposed rats were manifested by decreased SPT ratio, increased FST immobility time, decreased total distance, vertical movement score, and activity time of OFT. Hypothalamic neuroinflammation in CUMS-exposed rats was manifested by an amoebic-like activated state of microglia, downregulated expression of α7nAchR, p-JAK2, p-STAT3, and upregulated expression of NF-κB p65, p-NF-κB p65, and IL-1ß. TaVNS could significantly reverse the above-mentioned phenomena, but had a poor improvement effect for CUMS-exposed α7nAchR-/- rats. CONCLUSION: The hypothalamic α7nAchR/JAK2/STAT3/NF-κB signaling pathway may play an important role in the antidepressant-like behavior of taVNS.

Mapping the modulating effect of transcutaneous auricular vagus nerve stimulation on voxel-based analyses in patients with first-episode major depressive disorder: a resting-state functional magnetic resonance imaging study.

INTRODUCTION: Seed-based analysis has shown that transcutaneous auricular vagus nerve stimulation (taVNS) can modulate the dysfunctional brain network in patients with major depressive disorder (MDD). However, the voxel-based neuropsychological mechanism of taVNS on patients with first-episode MDD is poorly understood. The objective of this study was to assess the effects of an 8-week course of taVNS on patients with first-episode MDD. METHODS: Twenty-two patients with first-episode MDD accepted an 8-week course of taVNS treatment. Resting-state functional magnetic resonance imaging (rs-fMRI) scans were performed before and after treatment. Voxel-based analyses were performed to characterize spontaneous brain activity. Healthy controls (n=23) were recruited to minimize test-retest effects. Analysis of covariance (ANCOVA) was performed to ascertain treatment-related changes. Then, correlations between changes in brain activity and the Hamilton Depression Rating Scale (HAM-D)/Hamilton Anxiety Scale (HAM-A) remission rate were estimated. RESULTS: Significant group-by-time interactions on voxel-based analyses were observed in the inferior ventral striatum (VSi) and precuneus. Post-hoc analyses showed that taVNS inhibited higher brain activity in the VSi, while upregulating it in the precuneus. Functional connectivity (FC) between the VSi and precuneus decreased. Positive correlations were found between the HAM-D remission rate and changes in brain activity in the VSi. CONCLUSION: taVNS reduced the FC between VSi and precuneus by normalizing the abnormal spontaneous brain activity of VSi in first-episode MDD patients.

Acupuncture for brain diseases: Conception, application, and exploration.

The brain is probably the most complex organ in the human body. It has been the hot spot and direction of brain science research all over the world to deeply study the pathogenesis of various kinds of brain diseases and find effective treatment methods. Acupuncture is a nonpharmacological therapy of traditional Chinese medicine originating from ancient clinical practice. The research on the treatment of brain diseases by acupuncture has been constantly enriched and updated with the promotion of interdisciplinary research. In order to account for the current achievements in the field of acupuncture for brain diseases, this article reviews it in terms of conception, application, and exploration. Based on the literature review, we found that in the past decades, acupuncture has received widespread attention worldwide and many literatures have reported the clinical efficacy and underlying mechanisms of acupuncture in the treatment of brain diseases. Presently, the conception, application, and exploration of acupuncture in the treatment of brain diseases have evolved from empirical medicine to evidence-based medicine and precision medicine, and are experiencing a deeper understanding of the information about acupuncture regulating the brain function based on interdisciplinary research.

Does acupuncture therapy affect peripheral inflammatory cytokines of major depressive disorder? A protocol for the systematic review and meta-analysis.

Background: Acupuncture is widely used as adjuvant therapy for major depressive disorder (MDD). There is robust evidence that inflammation is closely associated with MDD. To date, only a few numbers of studies have investigated the potential relationship between acupuncture and the change of inflammatory biomarkers in patients with MDD. Additionally, the results are inconsistent among studies. The current study aims to provide a comprehensive, systematic review of the association between acupuncture and changes in peripheral inflammation of patients with MDD, and clarify the alterations of inflammatory cytokines before and after acupuncture treatment by meta-analysis. Methods and analysis: This study will be conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eligible randomized controlled trials (RCTs) reporting acupuncture, with inflammatory cytokines as the outcome measured before and after intervention in patients with MDD, were searched in electronic databases, such as PubMed, Embase, Cochrane, SINOMED, Wanfang, China national knowledge infrastructure (CNKI), and Chongqing VIP (CQVIP). Primary outcomes of interest will be validated to measure the levels of inflammatory cytokines before and after acupuncture treatment in patients with MDD. Discussion: Acupuncture can drive anti-inflammatory effects, as well as symptom changes in MDD, which may represent a viable, multi-faceted treatment approach in MDD. Systematic review registration: [PROSPERO], identifier [CRD42021289207 on 04 December 2021].

The efficacy and safety of transcutaneous auricular vagus nerve stimulation in patients with mild cognitive impairment: A double blinded randomized clinical trial.

BACKGROUND: There are 9.9 million new cases of dementia in the world every year. Short-term conversion rate from mild cognitive impairment (MCI) to dementia is between 20% and 40%, but long-term in 5-10 years ranges from 60% to 100%. It is particularly important to prevent or prolong the development of MCI into dementia. Both auriculotherapy and vagus nerve stimulation are effective on improving cognitive functions. However, there is no double blinded randomized clinical trial to support the effectiveness of transcutaneous electrical stimulation of auricular acupoints in patients with MCI. METHODS: This randomized controlled trial involved patients with MCI, aged from 55 to 75 years old. Patients were randomly allocated to transcutaneous auricular vagus nerve stimulation (taVNS) group or sham taVNS group. In the taVNS group, two auricular acupoints were stimulated, including heart (concha, CO15) and kidney (CO10), which are in the distribution of vagus nerve. While in the sham taVNS group, two other auricular acupoints were stimulated, including elbow (scaphoid fossa, SF3) and shoulder (SF4,5), which are out of the distribution of vagus nerve. The primary outcome was the Montreal cognitive assessment-basic, MOCA-B. The secondary outcomes included auditory verbal learning test-HuaShan version (AVLT-H), shape trails test A&B (STT-A&B), animal fluence test (AFT), Boston naming test (BNT), Pittsburgh sleep quality index (PSQI), rapid eye movement sleep behavior disorder screening questionnaire (RBDSQ), Epworth sleepiness scale (ESS) and functional activities questionnaire (FAQ). These outcome measures were taken at baseline, 24 weeks later. RESULTS: After 24 weeks of intervention, the data of 52 patients were intended for analysis. After intervention, there was significant difference in the overall scores of MoCA-B between taVNS group and sham taVNS group (p = 0.033 < 0.05). In taVNS group, compared with before intervention, the overall scores of MOCA-B increased significantly after intervention (p < 0.001). As for N5 and N7, the two sub-indicators of AVLT-H, in taVNS group, compared with before intervention, both N5 and N7 increased significantly after intervention (both ps < 0.001). As for STTB, in taVNS group, compared with before intervention, STTB was significantly reduced after intervention (p = 0.016). For BNT, in taVNS group, compared with before intervention, BNT increased significantly after intervention (p < 0.001). In taVNS group, compared with before intervention, PSQI, RBDSQ, ESS and FAQ decreased significantly after intervention (p = 0.002, 0.025, <0.001, 0.006 respectively). 1 patient with a history of tympanic membrane perforation in taVNS group was reported with mild adverse reactions which disappeared a week after termination of taVNS. The intervention of taVNS is effective on increasing the overall scores of MoCA-B, N5 and N7. CONCLUSION: The clinical trial demonstrated that taVNS can improve cognitive performance in patients with MCI. This inexpensive, effective and innovative method can be recommended as a therapy for more patients with MCI in the prevention or prolonging of its development into dementia, but it is still required to be further investigated. TRIAL REGISTRATION: http://www.chictr.org.cn. (ID: ChiCTR2000038868).

An assessor-blinded, randomized comparative trial of transcutaneous auricular vagus nerve stimulation (taVNS) combined with cranial electroacupuncture vs. citalopram for depression with chronic pain.

Background: Depression accompanying chronic pain (CP) is one of the most common comorbid psychiatric disorders. This study aimed to investigate the effectiveness of transcutaneous auricular vagus nerve stimulation (taVNS) combined with electroacupuncture at Baihui (GV20) and Yintang (GV29) acupoints compared with citalopram. Methods: Sixty patients with depression and pain comorbidity were enrolled in a prospective 8-week, single-blind, randomized controlled trial. Participants were randomly assigned to receive either taVNS combined with electroacupuncture treatment (taVNS: 8 weeks, 3 sessions per week; electroacupuncture: 8 weeks, twice per day, no drugs) or citalopram treatment (8 weeks, 40 mg/day). The primary outcome was Montgomery-Åsberg Depression Rating Scale (MADRS). The secondary endpoints were evaluated using the McGill Pain Questionnaire (SF-MPQ), self-reported 36-Item Short Form Survey (SF-36), Pittsburgh Sleep Quality Index (PSQI), Hamilton Depression Rating Scale (HAMD) and Hamilton Anxiety Scale (HAMA). Results: Both the taVNS combined with electroacupuncture and citalopram groups had significant reductions in depressive and pain symptoms, as indicated by the decrease in MARDS and SF-MPQ scores. Regarding the analgesic effect, the pain intensity score of the SF-MPQ showed a larger reduction with citalopram than with taVNS combined with electroacupuncture at 6 weeks (P = 0.036). The reduction in the BP score of the SF-36 was higher at week 4 (P = 0.000), with no significant difference observed at week 8 (P = 0.1110). This result indicated that the pain intensity can be improved rapidly with citalopram compared with taVNS combined with electroacupuncture. Similarly, the comparison of PSQI scores at 4, 6, and 8 weeks indicates that there was no significant difference between groups, except in the use of sleeping medications. At week 6, higher medication use was found in the citalopram group than in the taVNS combined with electroacupuncture group (P = 0.049). Conclusion: In summary, compared with citalopram, taVNS combined with electroacupuncture produces similar positive effects on depressive and pain symptoms in patients with depression and chronic pain, which last for at least 8 weeks.

[Effect of transcutaneous auricular vagus nerve stimulation on nocturnal autonomic nervous function in primary insomnia patients].

OBJECTIVE: To observe the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on the sleep quality and nocturnal heart rate variability (HRV) in patients with primary insomnia. METHODS: Twenty-one patients with primary insomnia were included. Using SDZ-ⅡB electric acupuncture apparatus, Xin (CO15) and Shen (CO10) were stimulated with disperse-dense wave, 4 Hz/ 20 Hz in frequency, (0.2±30%) ms of pulse width and tolerable intensity. Electric stimulation was given once every morning and evening of a day, 30 min each time, for 4 weeks totally. Before and after treatment, the score of Pittsburgh sleep quality index (PSQI), objective sleep structure (total sleep time [TST], sleep latency [SL], wake after sleep onset [WASO], sleep efficiency [SE], the percentages of non-rapid eye movement period 1, 2, 3, and the percentage of rapid eye movement period to TST [N1%, N2%, N3%, REM%] ) and nocturnal HRV (high frequency [HF], low frequency [LF], the ratio of LF to HF [LF/HF], standard deviation for the normal RR intervals [SDNN], squared root of the mean sum of squares of differences between adjacent intervals RR [RMSSD], the percentage of adjacent RR intervals with differences larger than 50 ms in the entire recording [PNN50%], the mean of sinus RR intervals [NNMean] ) were compared in the patients separately. RESULTS: After treatment, the score of each item and the total score of PSQI and SL were all reduced as compared with those before treatment (P<0.01, P<0.001); SE, N3%, LF, HF, LF/HF, SDNN, NNMean and RMSSD were all increased compared with those before treatment (P<0.001, P<0.01). CONCLUSION: The taVNS improves the sleep quality and objective sleep structure in patients with primary insomnia, which is probably related to the regulation of autonomic nervous functions.

[Transcutaneous auricular vagus nerve stimulation promotes gastric motility by up-rgulating α7nAChR and suppressing NF-κB p65 expression in duodenum in rats with functional dyspepsia].

OBJECTIVE: To study the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on gastric sensitivity and motility in rats with functional dyspepsia (FD), so as to explore its underlying mechanism in improving FD. METHODS: A total of 48 young SD rats were randomly divided into control (n=10), model (n=9), taVNS (n=9), subdiaphragmatic vagus nerve stimulation (SDVNS, n=9) and sham SDVNS (n=7) groups. The FD model was established by gavage of 0.1% iodoa-cetamide+2% glucose, once daily for 6 days. Rats in the taVNS group received taVNS (0.5 mA) of optopoint "Heart" and "Stomach" for 30 min, once daily for 14 days, while rats in the SDVNS group received subdiaphragmatic vagus nerve stimulation through the implanted electrode, and those of the sham SDVNS group received only application of the same electrodes without electrical stimulation. Electromyogram (EMG) of the cervical trapezius muscle (reflecting gastric sensitivity) was recorded before and after intragastric expansion via an air ballon and the gastric emptying rate was calculated for assessing the gastric motility. The contents of acetylcholine (ACh), nicotinic acetylcholine receptor α7 subunit (α7nAChR), interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) in the duodenum tissue were detected by enzyme-linked immunosorbent assay (ELISA). The expression of nuclear factor kappa B (NF-κB) p65 in the duodenum tissue was determined by Western blot. RESULTS: In comparison with the control group, the EMG change rate at intragastric pressure levels of 40, 60 and 80 mm Hg, expression of NF-κB p65 protein, and contents of IL-6, IL-1ß and TNF-α were significantly increased (P<0.05,P<0.01, P<0.001), while the gastric emptying rate, ACh and α7nAChR contents considerably decreased (P<0.05, P<0.001) in the model group. After interventions, the EMG change rate, contents of IL-6, IL-1ß and TNF-α, and expression of NF-κB p65 were notably decreased (P<0.05, P<0.01, P<0.001), and the gastric emptying rate, ACh and α7nAChR contents obviously increased (P<0.05, P<0.001) in both taVNS and SDVNS groups relevant to the model group. In comparison with the sham SDVNS group, the EMG change rate, contents of IL-6, IL-1ß and TNF-α, and expression of NF-κB p65 were notably decreased (P<0.01, P<0.05,P<0.001), and the gastric emptying rate, ACh and α7nAChR contents obviously increased (P<0.01, P<0.001) in the both SDVNS and taVNS groups. CONCLUSION: taVNS can reduce gastric sensitivity and promote gastric emptying in FD model rats, which may be closely related to its functions in up-regulating ACh and α7nAChR contents and inhibiting the activation of NF-κB p65 signaling in the duodenum.

Toward Diverse or Standardized: A Systematic Review Identifying Transcutaneous Stimulation of Auricular Branch of the Vagus Nerve in Nomenclature.

OBJECTIVES: After 20 years of development, there is confusion in the nomenclature of transcutaneous stimulation of the auricular branch of the vagus nerve (ABVN). We performed a systematic review of transcutaneous stimulation of ABVN in nomenclature. MATERIALS AND METHODS: A systematic search of the literature was carried out, using the bibliographic search engine PubMed. The search covered articles published up until June 11, 2020. We recorded the full nomenclature and abbreviated nomenclature same or similar to transcutaneous stimulation of ABVN in the selected eligible studies, as well as the time and author information of this nomenclature. RESULTS: From 261 studies, 67 full nomenclatures and 27 abbreviated nomenclatures were finally screened out, transcutaneous vagus nerve stimulation and tVNS are the most common nomenclature, accounting for 38.38% and 42.06%, respectively. In a total of 97 combinations of full nomenclatures and abbreviations, the most commonly used nomenclature for the combination of transcutaneous vagus nerve stimulation and tVNS, accounting for 30.28%. Interestingly, the combination of full nomenclatures and abbreviations is not always a one-to-one relationship, there are ten abbreviated nomenclatures corresponding to transcutaneous vagus nerve stimulation, and five full nomenclatures corresponding to tVNS. In addition, based on the analysis of the usage habits of nomenclature in 21 teams, it is found that only three teams have fixed habits, while other different teams or the same team do not always use the same nomenclature in their paper. CONCLUSIONS: The phenomenon of confusion in the nomenclature of transcutaneous stimulation of ABVN is obvious and shows a trend of diversity. The nomenclature of transcutaneous stimulation of ABVN needs to become more standardized in the future.

Comparative Effectiveness of Transcutaneous Auricular Vagus Nerve Stimulation vs Citalopram for Major Depressive Disorder: A Randomized Trial.

OBJECTIVES: Major depressive disorder (MDD) is one of the most common mental illnesses. This study aims to investigate the effectiveness of transcutaneous auricular vagus nerve stimulation (taVNS) compared with the effectiveness of citalopram, a commonly used antidepressant, in patients with depression. MATERIAL AND METHODS: A total of 107 male and female patients with MDD (55 in the taVNS group and 52 in the citalopram group) were enrolled in a prospective 12-week, single-blind, comparative effectiveness trial. Participants were recruited from the outpatient departments of three hospitals in China. Participants were randomly assigned to either taVNS treatment (eight weeks, twice per day, with an additional four-week follow-up) or citalopram treatment (12 weeks, 40 mg/d). The primary outcome was the 17-item Hamilton Depression Rating Scale (HAM-D17) measured every two weeks by trained interviewers blinded to the treatment assignment. The secondary end points included the 14-item Hamilton Anxiety Scale and peripheral blood biochemical indexes. RESULTS: The HAM-D17 scores were reduced in both treatment groups; however, there was no significant group-by-time interaction (95% CI: -0.07 to 0.15, p = 0.79). Nevertheless, we found that taVNS produced a significantly higher remission rate at week four and week six than citalopram. Both treatments were associated with significant changes in the peripheral blood levels of 5-hydroxytryptamine, dopamine, γ-aminobutyric acid, and noradrenaline, but there was no significant difference between the two groups. CONCLUSION: taVNS resulted in symptom improvement similar to that of citalopram; thus, taVNS should be considered as a therapeutic option in the multidisciplinary management of MDD. Nevertheless, owing to the design of this study, it cannot be ruled out that the reduction in depression severity in both treatment groups could be a placebo effect.

Transcutaneous auricular vagus nerve stimulators: a review of past, present, and future devices.

INTRODUCTION: As an emerging neuromodulation therapy, transcutaneous auricular vagus nerve stimulation (taVNS) has been proven to be safe and effective for epilepsy, major depressive disorders, insomnia, glucose metabolic disorders, pain, stroke, post stroke rehabilitation, anxiety, fear, cognitive impairment, cardiovascular disorders, tinnitus, Prader-Willi Syndrome, and COVID-19. AREAS COVERED: Although the history of taVNS is only two decades, the devices carrying taVNS technique have been constantly updated. Especially in recent years, the development of taVNS devices has presented a new trend. To conclude, the development of taVNS devices has entered a new era, thus the update speed and quality of taVNS devices will be considerably improved in the future. This article reviewed the history and classification of taVNS devices. EXPERT OPINION: The correlation between the effectiveness and stimulation parameters from taVNS devices still remains unclear. There is a lack of standard or harmonization among different taVNS devices. Strategies, including further comparative research and establishment of standard, have been recommended in this article to promote the future development of taVNS devices.

Efficacy and safety of acupuncture in the treatment of depression: A systematic review of clinical research.

As a common mental disorder, depression is one of the leading causes of disability around the world. Clinical studies have shown that acupuncture is an effective therapy without obvious side effects compared to limited efficacy and adverse reactions of drug therapy, cognitive behavioral therapy, and neuromodulation technology in treating depression. The objective of this review is to systematically evaluate whether acupuncture therapies for depression are safe and effective in order to provide a high-quality reference for clinical trials of acupuncture. A systematic search of the literature was carried out through bibliographic search engine PubMed. Subsequently, the study design, intervention methods, control group, results, and safety of acupuncture were analyzed. The results showed that acupuncture as an adjunct to antidepressants or as a single treatment can exert a positive impact on patients' depressive symptoms. Compared with antidepressants, acupuncture has the advantages of fast onset and long-term efficacy in the treatment of depression, and can enhance the efficacy of antidepressants. Moreover, the efficacy and safety of acupuncture in the treatment of depression maybe related to the qualification of the acupuncturist, the selection of acupoints, and intervention measures.

Effects of transcutaneous auricular vagus nerve stimulation on brain functional connectivity of medial prefrontal cortex in patients with primary insomnia.

As a representative of acupuncture and nonpharmaceutical therapy, auricular acupuncture has been widely for the treatment of insomnia. Transcutaneous auricular vagus nerve stimulation (taVNS) is a combination of auricular point stimulation and vagus nerve stimulation. It can not only treat primary insomnia effectively, but also is noninvasive, painless, portable and economical. The medial prefrontal cortex (mPFC) is a core region of default mode network (DMN), which is important for maintenance of sleep. However, the mechanism of taVNS in alleviating primary insomnia (PI) remains to be clarified. In this study, we found that taVNS could not only effectively reduce the score of Pittsburgh Sleep Quality Index, but also decreased functional connection (FC) between the left mPFC and bilateral dorsal anterior cingulate gyrus as well as FC between the right mPFC and the occipital cortex in patients with PI. Furthermore, the decrease in FC was positively correlated with the decline of sleep index score. Therefore, we proposed that treatment with taVNS can improve sleep quality and prolong sleep duration in patients with PI by reducing FC within DMN, FC between DMN and salience network, as well as FC between DMN and the occipital cortex. This may be one of mechanisms of taVNS in treating PI.

[Application prospect of common viral tracers in study on brain effect of acupuncture].

The feasibility and prospect of viral tracers and mediating functional components are explored in study on brain effect of acupuncture. In the paper, proceeding with viral tracers, the viral tracers used to analyze the structure of specific neural circuits are introduced, as well as their mediated probes, optical/chemical genetics techniques, Cre-LoxP systems, etc. The viral tracers and their functional components can not only mark specifically nerve cells or neural circuits, but also interfere with the function of specific types of neurons or nuclei. They solve some disadvantage of traditional nerve tracing method that only describes the morphology of neurons of one brain region and the simple projection among brain regions, and the indirect and non-specific absorption. The viral tracers and their functional components play the important approach to decoding the mechanism on brain effect of acupuncture when introduced in experimental acupuncture so as to provide an in vivo, real-time and intuitive novel method for a further analysis of neurobiological mechanism on brain effect of acupuncture.

Efficacy and safety assessment of severe COVID-19 patients with Chinese medicine: A retrospective case series study at early stage of the COVID-19 epidemic in Wuhan, China.

ETHNOPHARMACOLOGICAL RELEVANCE: The coronavirus disease 2019 (COVID-19) has formed a global pandemic since late 2019. Benefitting from the application experience of Chinese Medicine (CM) for influenza and SARS, CM has been used to save patients at the early stage of COVID-19 outbreak in China. AIM OF THE STUDY: In order to evaluate the efficacy and safety of CM, and compare with Western Medicine (WM) for COVID-19, we conducted a retrospective case series study based on the patients in Wuhan Jinyintan Hospital, Wuhan, China. METHODS: The inclusion and exclusion criteria of data extraction were set for this retrospective study. All patients who were admitted by the Wuhan Jinyintan Hospital between January 17th and February 25th 2020 were considered. In addition, patients enrolled met the severe defined by the guidelines released by the National Health Commission of the People's Republic of China. In these cases included in the study, CM or WM treatment was selected according to the wishes of the patients at the beginning of hospitalization. The patients in CM group were treated with Huashi Baidu granule (137 g po, bid) combined with the injections of Xiyanping (100 mg iv, bid), Xuebijing (100 ml iv, bid) and Shenmai (60 ml iv, qd) according to the syndrome of epidemic toxin blocking the lung in the theory of Traditional Chinese Medicine. The WM group received antiviral therapy (including abidor capsule 0.2 g po, tid; Lopinavir-Ritonavir tablets, 500 mg po, bid), antibiotics (such as cefoperazone 2 g iv, bid; moxifloxacin hydrochloride tablets, 0.4 g po, qd) or corticosteroid therapy (such as methylprednisolone succinate sodium 40 mg iv, qd; prednisone, 30 mg po, qd). In addition, patients in both groups received routine supportive treatment, including oxygen inhalation, symptomatic therapy, and/or human intravenous immunoglobulin, and/or serum albumin, and treatment for underlying diseases. The clinical outcomes were evaluated based on changes related with clinical manifestations, computer tomography (CT) scan images, and laboratory examinations before and after the treatment. RESULTS: 55 severe COVID-19 patients, with 23 in CM group and 32 in WM group, were included for analyzed. There was no case of death, being transferred to ICU, or receiving invasive mechanical ventilation in two groups during hospitalization. The median time of SARS-CoV-2 RNA clearance in CM and WM group were 12 days and 15.5 days respectively, the ratio of nucleic acid negative conversion of CM group at different follow-up time points was significantly higher than that of WM group (HR: 2.281, P = 0.018). Further, the chest CT imaging showed more widely lung lesion opacity absorbed in the CM group. The high sensitivity C-reactive protein and serum ferritin decreased significantly in the CM group (P<0.05). There was no significant difference in adverse events in terms of liver function and renal function between the two groups. CONCLUSION: Based on this retrospective analysis from Wuhan Jinyintan Hospital, CM has better effects in SARS-CoV-2 RNA clearance, promoting lung lesion opacity absorbed and reducing inflammation in severe COVID-19 patients, which is effective and safe therapy for treating severe COVID-19 and reducing mortality.

Transcutaneous Auricular Vagus Nerve Stimulation: From Concept to Application.

Whether in the West or the East, the connection between the ear and the rest of the body has been explored for a long time. Especially in the past century or more, the relevant theoretical and applied research on the ear has greatly promoted the development of ear therapy, and finally the concept of transcutaneous auricular vagus nerve stimulation (taVNS) has been proposed. The purpose of taVNS is to treat a disease non-invasively by applying electrical current to the cutaneous receptive field formed by the auricular branch of the vagus nerve in the outer ear. In the past two decades, taVNS has been a topic of basic, clinical, and transformation research. It has been applied as an alternative to drug treatment for a variety of diseases. Based on the rapid understanding of the application of taVNS to human health and disease, some limitations in the development of this field have also been gradually exposed. Here, we comprehensively review the origin and research status of the field.

[Effect of transcutaneous auricular vagus nerve stimulation on hyperglycemia and insulin receptors expression in impaired glucose tolerance rats].

OBJECTIVE: To explore the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on blood glucose regulation and the expression of insulin receptors (INR) of hypothalamus, liver and skeletal muscle tissues in impaired glucose tolerance (IGT) rats, so as to reveal its mechanisms underlying improvement of IGT. METHODS: Thirty-six male Wistar rats were randomly divided into control, model, transcutaneous auricular none-vagus nerve stimulation (tnVNS), and taVNS groups (n=9 in each group). The IGT model was established by feeding the rats with high-fat and high-sugar diet for 5 weeks, and subsequent intraperitoneal injection of a dose of streptozotocin (20 mg/kg). Transcutaneous electrostimulation (2 mA, 2 Hz/15 Hz) was applied to auricular concha (taVNS) or auricular margin (tnVNS), respectively. The treatment was conducted for 30 min once daily for 4 weeks. The body weight, fasting plasma glucose (FPG), 2 h plasma glucose (2 h PG) were recorded every week. The contents of plasma insulin (INS), glucagon (GC), glycosylated hemoglobin (GHbA1c) were detected by using enzyme linked immunosorbent assay (ELISA). The expression levels of INR in hypothalamus, liver and skeletal muscle tissues were detected by Western blot. RESULTS: After modeling, the rats' body weight, the contents of FPG, 2 h PG, GC and GHbA1c were significantly up-regulated (P<0.001, P<0.05, P<0.01), and the content of INS and expression of INR in hypothalamus, liver and skeletal muscle tissues were significantly down-regulated in the model group compared with the control group (P<0.001, P<0.01, P<0.05). Following the treatment, the increased FPG, 2 h PG, GC, and the decreased INS and INR expression of hypothalamus, liver and skeletal muscle tissues were apparently reversed in the taVNS group relevant to the model group (P<0.001, P<0.01, P<0.05). Compared with the tnVNS group, the FPG and 2 h PG contents were considerable decreased, and the content of INS and INR expression of hypothalamus and liver were obviously increased in the taVNS group (P<0.001, P<0.05, P<0.01). CONCLUSION: taVNS can improve the blood glucose and insulin sensitivity in IGT rats, which may contribute to its effectiveness in up-regulating the expression of INR in hypothalamus, liver and skeletal muscle tissues.

Effects of Transcutaneous Auricular Vagus Nerve Stimulation on Peripheral and Central Tumor Necrosis Factor Alpha in Rats with Depression-Chronic Somatic Pain Comorbidity.

Depression and pain disorders share a high degree of comorbidity. Inflammatory mechanisms play an important role in the pathogenesis of depression-chronic somatic pain comorbidity. In this study, we investigated the effects of acupuncture on blood and brain regional tumor necrosis factor alpha (TNF-α) in rats with depression and chronic somatic pain comorbidity. Forty Sprague-Dawley rats were randomly divided into the following 4 groups with 10 each: control, model, model treated with transcutaneous auricular vagus nerve stimulation (taVNS), and model treated with electroacupuncture (EA). Chronic unpredictable mild stress (CUMS) with chronic constriction injury of the sciatic nerve (CCI) was used to produce depression and chronic somatic pain comorbidity in the latter 3 groups. The rats of the taVNS and EA groups received, respectively, taVNS and EA at ST 36 for 28 days. Pain intensity was measured using a mechanical withdrawal threshold and thermal stimulation latency once biweekly. Depressive behavior was examined using a sucrose preference test at baseline and the end of modeling and intervention. The level of plasma TNF-α and the expression of TNF-α in the prefrontal cortex (PFC), hippocampus, amygdala, and hypothalamus were measured. While CUMS plus CCI produced remarkable depression-like behavior and pain disorders, EA and taVNS significantly improved depression and reduced pain intensity. CUMS plus CCI also resulted in a significant increase in plasma TNF-α level and the expression in all brain regions examined compared to the intact controls. Both EA and taVNS interventions, however, suppressed the elevated level of TNF-α. These results suggest that EA and taVNS have antidepressant and analgesic effects. Such effects may be associated with the suppression of TNF-α-related neuroinflammation.