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.

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

BACKGROUND: Depressive 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. DESIGN: One 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. DISCUSSION: This 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 REGISTRATION: Clinical Trials. ChiCTR-TRC-11001201 http://www.chictr.org/cn/

[Effect of electroacupuncture stimulation of auricular concha region at different time-points on behavior changes in depression rats].

UNLABELLED: OBJECTIVE To observe the effect of electroacupuncture (EA) stimulation of auricular concha region (ACR) on behavior changes of depression rats. METHODS: A total of 80 male Wistar rats were randomized into depression model (model, n = 6), EA-ACR (n = 12), preventive EA-ACR (Pre-EA-ACR, n = 11) and EA-ear-tip (n = 12) groups. Depression model was established by chronic unpredictable mild stress for 21 days and isolated breeding. Open-field test and sucrose solution intake preference test were conducted to assess changes of the rats' behavior activities before modeling and on day 22, 36 and 50 after starting model. For rats of the pre-EA-ACR group, EA (2 Hz, 1 mA) was applied to the bilateral auricular concha area for 20 min, once daily for 14 days, beginning from the 8th day on after starting model preparation till the end of the modeling, and for rats of the EA-ACR and EA-ear-tip groups, EA was given to the bilateral ACR and ear-tips respectively, beginning after modeling, once daily for 14 days. RESULTS: In comparison with pre-modeling, the percentages of sucrose solution consumption in rats of the model group decreased gradually from day 22 to 50 (P > 0.05). Compared with the model group,the percentage of sucrose solution consumption in the EA-ACR group was increased significantly on day 50 (P < 0.05), suggesting an inhibitory effect of EA on the reduction of sucrose intake preference at this time-point. No significant differences were found between the pre-EA-ACR and the model groups and between the EA-ear-tip and model groups as well as between the EA-ACR and model groups at most time-points (P > 0.05). Open-field test showed that in comparison with pre-modeling in the same one group, the total scores, crossing and rearing scores on day 22 were decreased considerably in the model and EA-ear-tip groups (P < 0.05, P < 0.01), rather than in the pre-EA-ACR and EA-ARC groups (P > 0.05), suggesting a suppressing effect of pre-EA-ACR and EA-ACR on depression behavior. Compared to day 22 in the same one group, the total scores, crossing and rearing scores on day 36 and 50 in the pre-EA-ACR and EA-ear-tip groups were decreased significantly (P < 0.05, P < 0.01). CONCLUSION: EA of auricular concha region can restrain the development of depression behavioral status in depression rats, which is superior to that of EA of ear-tip.