Hui Ben

A C-fiber reflex inhibition induced by electroacupuncture with different intensities applied at homotopic and heterotopic acupoints in rats selectively destructive effects on myelinated and unmyelinated afferent fibers

The aims of this study were to explore the C-fiber reflex inhibition induced by electroacupuncture with different intensities applied at homotopic or heterotopic acupoints, and to determine the influence selectively destroyed myelinated and unmyelinated afferent fibers on the C-fiber reflex inhibition. In the ipsilateral local acupoint, the general behavior of the C-fiber reflex can be depressed by electroacupuncture below the threshold of Adelta-fiber activation. Electroacupuncture stimulation within the intensity of Adelta-fiber activation applied to the ipsilateral limb pretreated with cobra venom did not elicit inhibition of C-fiber reflex in rats with demyelinated sciatic nerve. However, heterotopic electroacupuncture below the threshold of Adelta-fiber activation was totally ineffective. In contralateral heterotopic acupoints, the C-fiber reflex can be depressed only by electroacupuncture with stimulating intensities exceeding thresholds of Adelta and C-fiber activation. Electroacupuncture stimuli applied to capsaicin-pretreated limb in the intensities of threshold of Adelta-fiber and treble thresholds of C-fiber activation produced only a little inhibition of C-fiber reflex. Inhibitory intensity was roughly similar to that induced by the stimulation with intensity for the activation of Adelta-fiber in normal animal. In the spinalized animals transections at T6-T7 segments, regardless of intensities, the homotopic electroacupuncture stimulation only induced moderate depression of C-fiber reflex similar to that of Adelta-fiber activation; whereas, no matter what intensities of application, the inhibitory effects of C-fiber reflex disappeared totally by using heterotopic noxious electroacupuncture in these animals.

Acupuncture-like stimulation at auricular point Heart evokes cardiovascular inhibition via activating the cardiac-related neurons in the nucleus tractus solitarius.

Fifty-eight male Sprague-Dawley rats used in the present study to investigate the role of baroreceptor sensitive neurons of the nucleus tractus solitarius (NTS) in the regulation of cardiovascular inhibition during acupuncture at the auricular point Heart, single unit recording was made in anesthetized Sprague-Dawley rats. A neuron was considered to be excited or inhibited by acupuncture stimulation if it displayed 15% more or less spikes s(-1), respectively. NTS neurons were classified into cardiac-related (CR) neurons and non-cardiac-related neurons based on whether their rhythmic discharges were synchronized with the R-waves and responding to sodium nitroprusside (NP; 20 μg/kg, i.v.) administration. Manual acupuncture was applied at the auricular point Heart and somatic acupuncture points ST36 and PC6. Acupuncture at auricular point Heart showed a more significant inhibitory effect on arterial pressure (-22.1±2.4mm Hg; P<0.001) and heart rate (-12.7±1.7 bpm; P<0.001) than that at ST36 and PC6. Acupuncture at auricular point Heart also increased the level of response of CR neurons in the NTS (93.8%±26.0% increase in discharge rate; P<0.01). Systemic or local administration of atropine attenuated the cardiovascular inhibition and activation of CR neurons evoked by auricular acupuncture, but had no effect on the same responses evoked by somatic acupuncture. Inactivation of the NTS with local anesthetics also decreased the cardiovascular inhibitory responses evoked by auricular acupuncture. Our results show that acupuncture at the auricular point Heart regulates cardiovascular function by activating baroreceptor sensitive neurons in the NTS in a similar manner as the baroreceptor reflex in cardiovascular inhibition.

Transcutaneous vagus nerve stimulation for the treatment of depression: a study protocol for a double blinded randomized clinical trial

BackgroundDepressive disorders are the most common form of mental disorders in community and health care settings. Unfortunately, the treatment of Major Depressive Disorder (MDD) is far from satisfactory. Vagus nerve stimulation (VNS) is a relatively new and promising physical treatment for depressive disorders. One particularly appealing element of VNS is the long-term benefit in mood regulation. However, because this intervention involves surgery, perioperative risks, and potentially significant side effects, this treatment has been limited to those patients with treatment-resistant depression who have failed medication trials and exhausted established somatic treatments for major depression, due to intolerance or lack of response.This double-blinded randomized clinical trial aims to overcome these limitations by introducing a novel method of stimulating superficial branches of the vagus nerve on the ear to treat MDD. The rationale is that direct stimulation of the afferent nerve fibers on the ear area with afferent vagus nerve distribution should produce a similar effect as classic VNS in reducing depressive symptoms without the burden of surgical intervention.DesignOne hundred twenty cases (60 males) of volunteer patients with mild and moderate depression will be randomly divided into transcutaneous vagus nerve stimulation group (tVNS) and sham tVNS group. The treatment period lasts 4 months and all clinical and physiological measurements are acquired at the beginning and the end of the treatment period.DiscussionThis study has the potential to significantly extend the application of VNS treatment for MDD and other disorders (including epilepsy, bipolar disorder, and morbid obesity), resulting in direct benefit to the patients suffering from these highly prevalent disorders. In addition, the results of this double-blinded clinical trial will shed new light on our understanding of acupuncture point specificity, and development of methodologies in clinical trials of acupuncture treatment.Trials registrationClinical Trials. ChiCTR-TRC-11001201 http://www.chictr.org/cn/

The auriculo-vagal afferent pathway and its role in seizure suppression in rats

BackgroundThe afferent projections from the auricular branch of the vagus nerve (ABVN) to the nucleus tractus solitaries (NTS) have been proposed as the anatomical basis for the increased parasympathetic tone seen in auriculo-vagal reflexes. As the afferent center of the vagus nerve, the NTS has been considered to play roles in the anticonvulsant effect of cervical vagus nerve stimulation (VNS). Here we proposed an “auriculo-vagal afferent pathway” (AVAP), by which transcutaneous auricular vagus nerve stimulation (ta-VNS) suppresses pentylenetetrazol (PTZ)-induced epileptic seizures by activating the NTS neurons in rats.ResultsThe afferent projections from the ABVN to the NTS were firstly observed in rats. ta-VNS increased the first grand mal latency of the epileptic seizure and decreased the seizure scores in awake rats. Furthermore, when the firing rates of the NTS neurons decreased, epileptiform activity manifested as electroencephalogram (EEG) synchronization increased with 0.37±0.12 s delay in anaesthetized rats. The change of instantaneous frequency, mean frequency of the NTS neurons was negative correlated with the amplitude of the epileptic activity in EEG traces. ta-VNS significantly suppressed epileptiform activity in EEG traces via increasing the firing rates of the neurons of the NTS. In comparison with tan-VNS, the anticonvulsant durations of VNS and ta-VNS were significantly longer (P<0.01). There was no significant difference between the anticonvulsant durations of VNS and ta-VNS (P>0.05). The anticonvulsant effect of ta-VNS was weakened by reversible cold block of the NTS.ConclusionsThere existed an anatomical relationship between the ABVN and the NTS, which strongly supports the concept that ta-VNS has the potential for suppressing epileptiform activity via the AVAP in rats. ta-VNS will provide alternative treatments for neurological disorders, which can avoid the disadvantage of VNS.

Effects of Electroacupuncture at Auricular Concha Region on the Depressive Status of Unpredictable Chronic Mild Stress Rat Models

To explore new noninvasive treatment options for depression, this study investigated the effects of electroacupuncture (EA) at the auricular concha region (ACR) of depression rat models. Depression in rats was induced by unpredictable chronic mild stress (UCMS) combined with isolation for 21 days. Eighty male Wistar rats were randomly assigned into four groups: normal, UCMS alone, UCMS with EA-ACR treatment, and UCMS with EA-ear-tip treatment. Rats under inhaled anesthesia were treated once daily for 14 days. The results showed that blood pressure and heart rate were significantly reduced in the EA-ACR group than in the UCMS alone group or the EA-ear-tip group. The open-field test scores significantly decreased in the UCMS alone and EA-ear-tip groups but not in the EA-ACR group. Both EA treatments downregulated levels of plasma cortisol and ACTH in UCMS rats back to normal levels. The present study suggested that EA-ACR can elicit similar cardioinhibitory effects as vagus nerve stimulation (VNS), and EA-ACR significantly antagonized UCMS-induced depressive status in UCMS rats. The antidepressant effect of EA-ACR is possibly mediated via the normalization of the hypothalamic-pituitary-adrenal (HPA) axis hyperactivity.

Effect of transcutaneous auricular vagus nerve stimulation on major depressive disorder: A nonrandomized controlled pilot study

BACKGROUND Depression presents a significant burden to both patients and society. One treatment that has emerged is vagus nerve stimulation (VNS), an FDA-approved physical treatment for depressive disorders. However, the application of this intervention has been limited by the involvement of surgery and potential side effects. The aim of this study is to explore the effectiveness of stimulating the superficial branches of the vagus nerve as a solo treatment for MDD. METHODS This is a nonrandomized, controlled study. The first cohort of patients (n=91) only received transcutaneous auricular VNS (taVNS) for 12 weeks. In the second cohort (n=69), patients first received 4 weeks of sham taVNS followed by 8 weeks of taVNS. All treatments were self-administered by the patients at home after they received training from the hospitals. The primary outcome measurement was the 24-item Hamilton Depression Rating Scale measured at weeks 0, 4, 8, and 12. Data analysis included a timelag analysis comparing (1) real and sham taVNS groups at week 4; (2) the real taVNS group at week 4 vs the sham taVNS group at week 8 (fourth week of real taVNS following 4 weeks of sham); and (3) the real taVNS group at week 8 vs the sham taVNS group at week 12 (eighth week of real taVNS following sham). RESULTS After four weeks of treatment, MDD patients in the taVNS group showed greater improvement than patients in the sham taVNS group as indicated by Hamilton score changes as well as response and remission rates at week four. In addition, we also found that the clinical improvements continued until week 12 during taVNS. LIMITATIONS Patients were not randomized in this study. CONCLUSIONS Our results suggest that taVNS is a promising, safe, and cost-effective therapeutic method for mild and moderate MDD.

Auricular Acupuncture May Suppress Epileptic Seizures via Activating the Parasympathetic Nervous System: A Hypothesis Based on Innovative Methods.

Auricular acupuncture is a diagnostic and treatment system based on normalizing the bodys dysfunction. An increasing number of studies have demonstrated that auricular acupuncture has a significant effect on inducing parasympathetic tone. Epilepsy is a neurological disorder consisting of recurrent seizures resulting from excessive, uncontrolled electrical activity in the brain. Autonomic imbalance demonstrating an increased sympathetic activity and a reduced parasympathetic activation is involved in the development and progress of epileptic seizures. Activation of the parasympathetic nervous system such as vagus nerve stimulation has been used for the treatment of intractable epilepsy. Here, we propose that auricular acupuncture may suppress epileptic seizures via activating the parasympathetic nervous system.

Transcutaneous Auricular Vagus Nerve Stimulation Protects Endotoxemic Rat from Lipopolysaccharide-Induced Inflammation

Background. Transcutaneous auricular vagus nerve stimulation (ta-VNS) could evoke parasympathetic activities via activating the brainstem autonomic nuclei, similar to the effects that are produced after vagus nerve stimulation (VNS). VNS modulates immune function through activating the cholinergic anti-inflammatory pathway. Methods. VNS, ta-VNS, or transcutaneous electrical acupoint stimulation (TEAS) on ST36 was performed to modulate the inflammatory response. The concentration of serum proinflammatory cytokines and tissue NF-kappa B p65 (NF-κB p65) were detected in endotoxaemia affected anesthetized rats. Results. Similar to the effect of VNS, ta-VNS suppressed the serum proinflammatory cytokines levels, such as tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) as well as NF-kappa B p65 expressions of lung tissues. ST36 stimulation also decreases LPS-induced high TNF-α level and NF-κB signal, but it did not restrain proinflammatory cytokine IL-1β and IL-6. Neither ta-VNS nor ST36 stimulation could suppress LPS-induced TNF-α and NF-κB after vagotomy or with α7nAChR antagonist injection. Conclusions. The present paper demonstrated that ta-VNS could be utilized to suppress LPS-induced inflammatory responses via α7nAChR-mediated cholinergic anti-inflammatory pathway.

Mechanism of acupuncture regulating visceral sensation and mobility.

Chinese ancient medical scientists have long focused on the internal and external contacts between acupoints on the surface of the body and the viscera. The Miraculous Pivot (it is one of the earliest medical classics in China) stated, “Twelve regular channels belong to the zang-fu organs internally, and connect to the extremities and joints externally.” Traditional Chinese medicine considers acupoints as defined areas where the Qi of viscera and meridians are transfused. These include the reaction points of visceral diseases on the body surface as well as the acupuncture trigger points that promote the flow of Qi and blood, and regulate visceral function. Chinese ancient medical scientists classified the specificity of the main acupoints in the body based on the meridian doctrine, which has been instructing clinical application for about 2000 years. Laws on the domino effect of acupoints have mainly focused on conclusions to clinical experiences. Indications of some acupoints exceed the practical paradigm since the excessive extension occurred during theory derivation. The current research direction on acupuncture focuses on three aspects: the effectiveness of acupuncture and moxibustion; the relevances and associations between meridians and viscera; and the physical and chemical properties and relevant physical basis of acupoints. The relevance between meridians and viscera is the central theory in the meridian doctrine, and acupoints are regarded as an important link in the relationship between meridians and viscera. Specific relationships between acupoints and target organs exist. Stimulating different acupoints on the body surface can help deal with different diseases, especially visceral diseases. In addition, acupoints have a dual function of reflecting and treating visceral diseases. There is no systemic research available on acupoint specificity, despite current knowledge and clinical experiences, which results in a weak foundation for acupuncture theory. This study focuses on the relevance and associations between meridians and viscera. A summary of the mechanisms of acupuncture regulating visceral sensation and mobility and the specific relationships between acupoints and their target organs are presented in this review.

Observation of Pain-Sensitive Points along the Meridians in Patients with Gastric Ulcer or Gastritis

This study aims to investigate the sensitization of human skin points along certain meridians related to visceral disease by using the pressure-pain threshold (PPT) as an indicator. We detected and compared the PPTs of people with and without gastric ulcer or gastritis on the related acupoints, abdomen area, and back area with von Frey detector and observed the similarities and differences under their respective physiological and pathological states. The results showed that (1) the PPTs of patients with gastric ulcer on related acupoints decreased significantly compared with the control group; (2) there was no significant difference in PPT between the chosen points of the measured meridian and the adjacent nonacupoints; (3) there was an apparent distribution of tender points on the relevant abdomen and back regions of patients with gastric ulcer or gastritis, but none was found on the control group; (4) the pain-sensitive points of gastric ulcer and gastritis patients were BURONG (ST19), LIANGMEN (ST21), and HUAROUMEN (ST24) of the stomach meridian on the abdominal region and PISHU (BL20), WEISHU (BL21), and WEICANG (BL50) on the back, among others The results suggest that the practical significance of acupoints may lie in its role as a relatively sensitive functional area. In a pathological state, the reflex points on the skin which are related to certain visceral organs become sensitive and functionally intensify.