Low- and high-frequency transcutaneous electrical acupoint stimulation induces different effects on cerebral μ-opioid receptor availability in rhesus monkeys

Effects of Electroacupuncture at Varied Frequencies on Analgesia and Mechanisms in Sciatic Nerve Cuffing-Induced Neuropathic Pain Mice

Addressing the intricate challenge of chronic neuropathic pain has significant implications for the physical and psychological well-being of patients, given its enduring nature. In contrast to opioids, electroacupuncture (EA) may potentially provide a safer and more efficacious therapeutic alternative. Our objective is to investigate the distinct analgesic effects and potential mechanisms of EA at frequencies of 2 Hz, 100 Hz, and 18 kHz in order to establish more precise frequency selection criteria for clinical interventions. Analgesic efficacy was evaluated through the measurement of mice's mechanical and thermal pain thresholds. Spinal cord inflammatory cytokines and neuropeptides were quantified via Quantitative Real-time PCR (qRT-PCR), Western blot, and immunofluorescence. Additionally, RNA sequencing (RNA-Seq) was conducted on the spinal cord from mice in the 18 kHz EA group for comprehensive transcriptomic analysis. The analgesic effect of EA on neuropathic pain in mice was frequency-dependent. Stimulation at 18 kHz provided superior and prolonged relief compared to 2 Hz and 100 Hz. Our research suggests that EA at frequencies of 2 Hz, 100 Hz, and 18 kHz significantly reduce the release of inflammatory cytokines. The analgesic effects of 2 Hz and 100 Hz stimulation are due to frequency-dependent regulation of opioid release in the spinal cord. Furthermore, 18 kHz stimulation has been shown to reduce spinal neuronal excitability by modulating the serotonergic pathway and downstream receptors in the spinal cord to alleviate neuropathic pain.

Exploring the Rules of Related Parameters in Transcutaneous Electrical Nerve Stimulation for Cancer Pain Based on Data Mining

INTRODUCTION

This study aims to investigate the regularity of related parameters in the treatment of cancer pain using transcutaneous electrical nerve stimulation (TENS).

METHODS

A comprehensive literature search was conducted in databases such as PubMed, Cochrane Library, Embase, Web of Science, OVID, CNKI, CBM, VIP, and WANNGFANG from inception up to December 2022. A database was established, and data mining techniques were applied to analyze the relevant TENS parameters.

RESULTS

A total of 27 articles were included, encompassing nine current frequencies, four retention times, four treatment frequencies, and two wave types. On the basis of the analysis of parameter association rules, the most closely related parameter combination for clinical TENS in the treatment of cancer pain was a current frequency of 2/100 Hz, a treatment frequency of once a day, a retention time of 30 min, and the dilatational wave. Moreover, the study involved 22 acupuncture points distributed along 13 meridians. According to the analysis of acupuncture point association rules, Hegu (LI04), Zusanli (ST36), and Sanyinjiao (SP06) were the most closely related acupuncture points and could be used in combination for clinical TENS in cancer pain treatment. Furthermore, cluster analysis was conducted on acupuncture points with a frequency ≥ 5, resulting in three categories: the first category included Sanyinjiao (SP06), Zusanli (ST36), Hegu (LI04), Jiaji point, and Neiguan (PC06); the second category included Ashi point; and the third category included Back shu point.

CONCLUSION

In the treatment of cancer pain using TENS, it is recommended to use a current frequency of 2/100 Hz, a treatment frequency of once a day, a retention time of 30 min, and the dilatational wave. The electrode positions were primarily selected from Ashi point, Back shu point, Sanyinjiao (SP06), Zusanli (ST36), Hegu (LI04), Jiaji point, and Neiguan (PC06) to achieve the best analgesic effect.

Transcutaneous electrical acupoint stimulation for suspected laryngopharyngeal reflux disease

PURPOSE

To determine the efficacy of transcutaneous electrical acupoint stimulation (TEAS) combined with proton pump inhibitor (PPI) therapy on symptoms and signs of patients with suspected laryngopharyngeal reflux disease (LPRD).

METHODS

This was a prospective randomized controlled study. Seventy patients with reflux symptom index (RSI) > 13 and reflux finding score (RFS) > 7 were recruited and received PPI alone (control group) or TEAS combined with PPI (experimental group) for 12 weeks. Patients in the experimental group received TEAS at Tiantu (RN22), Renying (ST9), and Neiguan (PC6) once a day, five times a week. RSI, RFS, throat pain visual analog score (VAS), and LPR-health-related quality-of-life (LPR-HRQL) scores were evaluated at baseline and after 4 and 12 weeks.

RESULTS

The decreases in total RSI and RFS, along with several subscores, were significantly higher in the experimental group than in the control group after 12 weeks (P < 0.05). The throat pain VAS and LPR-HRQL scores decreased significantly at 4 and 12 weeks after treatment in both groups, with significant differences between the groups (P < 0.001). No severe adverse events occurred, and the rates of adverse events were similar between the two groups.

CONCLUSION

Compared with PPI alone, TEAS combined with PPI showed a significantly greater improvement in symptoms, signs, and quality of life in the treatment of LPRD without increasing the occurrence of adverse effects. Therefore, TEAS could serve as a useful and safe treatment method for LPRD.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2100046755.

The effects of pain relief on proprioception and muscle strength for tibial plateau fractures: A randomized controlled trial

OBJECTIVES

To investigate the effect of transcutaneous electrical acupoint stimulation (TEAS) combined with proprioceptive neuromuscular facilitation (PNF) on postural stability, muscle strength and pain in patients with tibial plateau fracture.

METHOD

A 3-arm randomized controlled trial was conducted in 60 patients with tibial plateau fracture. Participants received one of the following interventions: standard treatment (ST group, n = 20), ST + PNF training (ST + PNF group, n = 20), ST + PNF training + TEAS intervention (ST + PNF + TEAS group, n = 20). All treatments lasted for six weeks. Participants' postural stability, muscle strength and pain were evaluated at baseline, after 3 and 6 weeks of intervention.

RESULTS

After 3 weeks of intervention, Between-group comparisons showed that both the ST + PNF group and ST + PNF + TEAS group showed significantly greater performance than the ST group in the postural stability measure (P < 0.02) and pain score(P < 0.05). The peak torque of quadriceps extensors and flexors at the velocity of 60°/s was significantly higher in the ST + PNF + TEAS group than in the ST group (P < 0.02). After 6 weeks of intervention, only the ST + PNF + TEAS group was superior to the ST group in postural stability measure(P < 0.04) and in pain score (P < 0.05). The ST + PNF + TEAS group was significantly higher than the ST + PNF group and the ST group in the peak torque of quadriceps extensors at the velocity of 60°/s and 180°/s (P < 0.01).

CONCLUSION

PNF training could improve dynamic postural stability and relieve pain at three weeks, while TEAS combined with PNF was more effective in relieving pain, strengthening muscle strength and improving dynamic postural stability at six weeks post-intervention.

Effective Oriental Magic for Analgesia: Acupuncture

Pain is a kind of complex physiological and psychological symptom, which makes the person debilitated and uncomfortable. Some persistent pain is unbearable for the patients, reducing the quality of life and bringing considerable pressure to the individuals and society. Pain killers seem to be effective in analgesia for patients, but their safety and addiction are crucial issues. From the theory of traditional Chinese medicine (TCM), the blocked meridian is the main cause of pain, and effective acupuncture can play a positive analgesic effect. Acupuncture that can date back thousands of years is one of the ancient medical practices in China. Its safety and effectiveness are respected. Based on its superior safety and inferior side effects, it has been gradually recognized as a therapeutic intervention method for complementary medicine, which is also generally used to treat multiple pain diseases. It is shown by modern medical studies that neurotransmitters are the material basis for the acupuncture effect, and the effect of acupuncture analgesia is related to changes in neurotransmitters. However, the specific mechanism has not been elucidated. This review aims to comprehensively discuss the historical evolution of acupuncture analgesia, clinical research of acupuncture analgesia, comparison of acupuncture and drug therapy, the neurotransmitter mechanism of acupuncture analgesia, the effect of acupuncture manipulation on analgesia, and bibliometric analysis of acupuncture treatment for pain, to explore the superiority and related mechanism of acupuncture analgesia from different aspects, and to provide a more effective treatment for alleviating patients' pain.

Comparative effect of electroacupuncture with different frequency on headache attacks in migraine outpatients: study protocol for a randomised placebo-controlled trial

Background

Headache attacks severely impaired life quality and increase the economic burden of migraineurs. Electroacupuncture (EA) has been used worldwidely to treat several pain-related diseases including migraines. However, whether EA with low or high frequency exerts a distinct analgesic effect remains unknown and needs further study.

Methods/Design

This study is a randomised, single-blinded, placebo-controlled trial with three parallel arms. A total of 144 migraine outpatients will be randomly allocated to the 2 Hz EA group, 100 Hz EA group and placebo control group. The duration of the trial is 20 weeks, including a 4-week-long baseline assessment period (weeks − 4–0), a 4-week-long treatment period (weeks 1–4) and a 12-week-long follow-up period (weeks 5–16). Twelve treatment sessions will be performed over a 4-week period (weeks 1–4). The primary outcome will be measured by the frequency of migraine attacks in the past 4 weeks at the end of week 4 post-randomisation. The secondary outcome will be measured by the frequency of migraine attacks in the past 4 weeks at the end of weeks 8, 12 and16 post-randomisation; number of days with migraine; dosage of ibuprofen; the scores of visual analogue scale (VAS); Self-Rating Anxiety Scale (SAS); Self-Rating Depression Scale (SDS); and Migraine Specific Quality of Life questionnaire (MSQ) in the past 4 weeks at the end of weeks 4, 8, 12 and 16 post-randomisation. Safety assessment, compliance and blinding evaluation will be carried out at the end of week 16 post-randomisation.

Discussion

The recruitment will be started on 1 June 2021 and expected to finish on 31 May 2023. We aimed to clarify the dominant frequency of EA on headache attacks in a migraineur.

Trial registration

Chinese Clinical Trial Registry ChiCTR-1800017259. Registered on 20 July 2018. 

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05429-9.

Impact of Auricular Neurostimulation in Patients Undergoing Colorectal Surgery with an Enhanced Recovery Protocol: A Pilot Randomized, Controlled Trial

BACKGROUND

Narcotics are the cornerstone of postoperative pain control, but the opioid epidemic and the negative physiological and psychological effects of narcotics implore physicians to utilize nonpharmacological methods of pain control.

OBJECTIVE

This pilot study investigated a novel neurostimulation device for postoperative analgesia. We hypothesized that active neurostimulation would decrease postoperative narcotic requirements.

DESIGN

This was a placebo-controlled, double-blinded trial.

SETTINGS

This trial was conducted at an academic medical center and a Veterans Affairs hospital.

PATIENTS

This trial included adult patients who underwent elective bowel resection between December 2016 and April 2018.

INTERVENTIONS

Patients were randomly assigned to receive an active or inactive (sham) device, which was applied to the right ear before surgery and continued for 5 days.

MAIN OUTCOME MEASURES

The primary outcome was total opioid consumption. The secondary outcomes included pain, nausea, anxiety, return of bowel function, complications, 30-day readmissions, and opioid consumption at 2 weeks and 30 days.

RESULTS

A total of 57 patients participated and 5 withdrew; 52 patients were included in the analysis. Twenty-eight patients received an active device and 24 received an inactive device. There was no difference in total narcotic consumption between active and inactive devices (90.79 ± 54.93 vs 90.30 ± 43.03 oral morphine equivalents/day). Subgroup analyses demonstrated a benefit for patients after open surgery (p = 0.0278). When patients were stratified by decade, those aged 60 to 70 and >70 years derived a benefit from active devices in comparison with those aged 30 to 40, 40 to 50, and 50 to 60 years old (p = 0.01092). No serious adverse events were related to this study.

LIMITATIONS

This study was limited by the small sample sizes.

CONCLUSIONS

No difference in opioid use was found with auricular neurostimulation. However, this pilot study suggests that older patients and those with larger abdominal incisions may benefit from auricular neurostimulation. Further investigation in these high-risk patients is warranted. See Video Abstract at http://links.lww.com/DCR/B452.ClinicalTrials.gov identifier: NCT02892513.

IMPACTO DE LA NEUROESTIMULACIN AURICULAR EN PACIENTES SOMETIDOS A CIRUGA COLORRECTAL CON UN PROTOCOLO DE RECUPERACIN MEJORADA UN ENSAYO PILOTO ALEATORIZADO Y CONTROLADO

ANTECEDENTES:Los narcóticos son la piedra angular del control del dolor postoperatorio, pero la epidemia de opioides y los efectos fisiológicos y psicológicos negativos de los narcóticos incentivan a los médicos a que utilicen métodos no farmacológicos de control del dolor.OBJETIVO:Este estudio piloto investigó un nuevo dispositivo de neuroestimulación para analgesia postoperatoria. Hipotetizamos que la neuroestimulación activa disminuiría los requerimientos narcóticos postoperatorios.DISEÑO:Este fue un ensayo doble ciego controlado con placebo.ESCENARIO:Esto se llevó a cabo en un centro médico académico y en un hospital de Asuntos de Veteranos (Veterans Affairs hospital).PACIENTES:Este ensayo incluyó pacientes adultos que se sometieron a resección intestinal electiva entre diciembre de 2016 y abril de 2018.INTERVENCIONES:Los pacientes fueron asignados al azar para recibir un dispositivo activo o inactivo (falso), que se aplicó al oído derecho antes de la cirugía y se mantuvo durante 5 días.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue el consumo total de opioides; los resultados secundarios incluyeron dolor, náusea, ansiedad, retorno de la función intestinal, complicaciones, reingresos a 30 días y consumo de opioides a 2 semanas y a 30 días.RESULTADOS:Participaron un total de 57 pacientes y 5 se retiraron; Se incluyeron 52 pacientes en el análisis. Veintiocho pacientes recibieron un dispositivo activo y 24 recibieron un dispositivo inactivo. No hubo diferencias en el consumo total de narcóticos entre los dispositivos activos e inactivos (90.79 ± 54.93 vs 90.30 ± 43.03 equivalentes de morfina oral [OME] / día). Los análisis de subgrupos demostraron un beneficio para los pacientes después de cirugía abierta (p = 0.0278). Cuando los pacientes se estratificaron por década, aquellos de 60-70 y > 70 años obtuvieron un beneficio de los dispositivos activos en comparación con los de 30-40, 40-50 y 50-60 años (p = 0.01092). No hubo eventos adversos graves relacionados con este estudio.LIMITACIONES:Este estudio estuvo limitado por los pequeños tamaños de muestra.CONCLUSIONES:No se encontró diferencia en el uso de opioides con la neuroestimulación auricular. Sin embargo, este estudio piloto sugiere que los pacientes mayores y aquellos con incisiones abdominales más grandes pueden beneficiarse de la neuroestimulación auricular. Está justificada la investigación adicional en estos pacientes de alto riesgo. Consulte Video Resumen en http://links.lww.com/DCR/B452. (Traducción-Dr. Jorge Silva Velazco).

Electroacupuncture decreases inflammatory pain through a pro-resolving mechanism involving the peripheral annexin A1-formyl peptide receptor 2/ALX-opioid receptor pathway

The pro-resolving mechanism is a recently described endogenous process that controls inflammation. The present study evaluated components of this mechanism, including annexin 1 (ANXA1) and the formyl peptide receptor 2/ALX (FPR2/ALX) receptor, in the antihyperalgesic effect induced by electroacupuncture (EA) in an animal model of persistent peripheral inflammation. Male Swiss mice underwent intraplantar (i.pl.) injection with complete Freund's adjuvant (CFA). Mechanical hyperalgesia was assessed with von Frey monofilaments. Animals were treated with EA (2-10 Hz, ST36-SP6) or subcutaneous BML-111 injection (FPR2/ALX agonist) for 5 consecutive days. In a separate set of experiments, on the first and fifth days after CFA injection, animals received i.pl. WRW4 (FPR2/ALX antagonist) or naloxone (non-selective opioid receptor antagonist) before EA or BML-111 injection. Paw protein levels of FPR2/ALX and ANXA1 were evaluated on the second day after CFA injection by western blotting technique. EA and BML-111 reduced mechanical hyperalgesia. I.pl. naloxone or WRW4 prevented the antihyperalgesic effect induced by either EA or BML-111. EA increased ANXA1 but did not alter FPR2/ALX receptor levels in the paw. Furthermore, i.pl. pretreatment with WRW4 prevented the increase of ANXA1 levels induced by EA. This work demonstrates that the EA antihyperalgesic effect on inflammatory pain involves the ANXA1/FPR2/ALX pro-resolution pathway. This effect appears to be triggered by the activation of FPR2/ALX receptors and crosstalk communication with the opioid system.

Electro-Acupuncture Inhibits p66Shc-Mediated Oxidative Stress to Facilitate Functional Recovery After Spinal Cord Injury

Oxidative stress is the core problem in improving secondary spinal cord injury (SCI). To investigate the effect of electro-acupuncture with different frequencies on neuroinflammation, oxidative stress injury, as well as related signaling pathways, male Sprague-Dawley (SD) rats were induced using operation for model SCI and then treated with electrical stimulation at low frequency (2 mA, 0.2 Hz), medium frequency (2 mA, 50 Hz), and high frequency (2 mA, 100 Hz), respectively. Here, we first demonstrated that the JNK/p66^Shc signal pathway promoted ROS generation and inhibited the anti-oxidation effect of FoxO3a to induce oxidative stress damage after SCI and the mechanism of electro-acupuncture in anti-oxidative stress. Electro-acupuncture facilitated functional recovery after SCI and improved the apoptosis of neurons. Furthermore, p38MAPK-mediated microglia activation and inflammatory reaction and JNK/p66^Shc-mediated ROS generation and oxidative stress damage were both attenuated by electro-acupuncture. However, the inhibitory effect of electro-acupuncture on p38MAPK was enslaved to the acupuncture frequency, but the ROS generation and phosphorylation of p66^Shc were effectively inhibited by electro-acupuncture. Therefore, the activation of JNK/p66^Shc promoted the ROS-induced oxidative stress damage after SCI, and inhibiting the phosphorylation of p66^Shc-mediated oxidative stress was the key target of electro-acupuncture to facilitate functional recovery SCI, but not p38MAPK.

Efficacy of transcutaneous electrical acupoint stimulation combined with diazepam for acute alcohol withdrawal syndrome: A double-blind randomized sham-controlled trial

Objective

To compare the efficacy of transcutaneous electrical acupoint stimulation (TEAS) combined with diazepam against diazepam alone for treatment of acute alcohol withdrawal syndrome (AWS).

Methods

In this double-blind randomized sham-controlled trial, men with acute AWS were randomly allocated to either a group treated with TEAS combined with diazepam (n = 57) or a control group treated with sham TEAS combined with diazepam (n = 60). Treatment was performed at four acupoints twice a day for 14 days. The Clinical Institute Withdrawal Assessment for Alcohol Scale (CIWA-Ar), visual analogue scale (VAS), Pittsburgh Sleep Quality Index (PSQI) and modified Epworth Sleepiness Scale (mESS) were used to evaluate treatment efficacy.

Results

All scores improved significantly in both groups during the trial. CIWA-Ar scores were lower in the TEAS group than in the control group from day 3 until the end of observation. VAS and mESS scores were also lower in the TEAS group than in the control group on day 7. VAS and PSQI scores were lower in the TEAS group on day 14.

Conclusion

Combining diazepam with TEAS may result in milder AWS symptoms than diazepam alone, improve sleep quality and reduce sleepiness.

Acupuncture at Zusanli (ST36) for Experimental Sepsis: A Systematic Review

Background

Sepsis is a global major health problem with high mortality rates. More effective therapy is needed for treating sepsis. Acupuncture has been used for various diseases, including severe infection, in China for more than 2,000 years. Previous studies reported that acupuncture at Zusanli (ST36) might be effective in treating sepsis, but the efficacy and the quality of evidence remain unclear since there is no systematic review on acupuncture at ST36 for sepsis.

Methods

Seven databases were searched from the inception of each database up to May 2019. Ultimately, 54 studies using acupuncture at ST36 for the treatment of experimental sepsis were identified in both English and Chinese literature with systematic review procedures.

Results

Acupuncture might be useful in reducing injuries induced by sepsis in cardiac, lung, kidney, liver, gastrointestinal tract, and immune system. Its potential mechanisms for antisepsis might include reducing oxidative stress and inflammation, improving microcirculatory disturbance, and maintaining the immune balance mediated by dopamine. However, the positive findings should be interpreted with caution due to poor methodological quality and publication bias.

Conclusion

Acupuncture at ST36 might be a promising complementary strategy for controlling sepsis inflammation, yet further studies are needed.

A Survey of Molecular Imaging of Opioid Receptors

The discovery of endogenous peptide ligands for morphine binding sites occurred in parallel with the identification of three subclasses of opioid receptor (OR), traditionally designated as μ, δ, and κ, along with the more recently defined opioid-receptor-like (ORL1) receptor. Early efforts in opioid receptor radiochemistry focused on the structure of the prototype agonist ligand, morphine, although N-[methyl-¹¹C]morphine, -codeine and -heroin did not show significant binding in vivo. [¹¹C]Diprenorphine ([¹¹C]DPN), an orvinol type, non-selective OR antagonist ligand, was among the first successful PET tracers for molecular brain imaging, but has been largely supplanted in research studies by the μ-preferring agonist [¹¹C]carfentanil ([¹¹C]Caf). These two tracers have the property of being displaceable by endogenous opioid peptides in living brain, thus potentially serving in a competition-binding model. Indeed, many clinical PET studies with [¹¹C]DPN or [¹¹C]Caf affirm the release of endogenous opioids in response to painful stimuli. Numerous other PET studies implicate μ-OR signaling in aspects of human personality and vulnerability to drug dependence, but there have been very few clinical PET studies of μORs in neurological disorders. Tracers based on naltrindole, a non-peptide antagonist of the δ-preferring endogenous opioid enkephalin, have been used in PET studies of δORs, and [¹¹C]GR103545 is validated for studies of κORs. Structures such as [¹¹C]NOP-1A show selective binding at ORL-1 receptors in living brain. However, there is scant documentation of δ-, κ-, or ORL1 receptors in healthy human brain or in neurological and psychiatric disorders; here, clinical PET research must catch up with recent progress in radiopharmaceutical chemistry.

Electroacupuncture regulates the DREAM/NF-κB signalling pathway and ameliorates cyclophosphamide-induced immunosuppression in mice

BACKGROUND

Immune responses inhibit invasion by pathogens and antigens. Thus, it is important to promote the immune response in immunosuppressed patients.

OBJECTIVE

To examine whether electroacupuncture (EA) promotes the immune response by regulating the downstream regulatory element antagonist modulator / nuclear factor kappa B (DREAM/NF-κB) signalling pathway in a mouse model of cyclophosphamide (CP)-induced immunosuppression, and determine the most effective frequency.

METHODS

Twenty-four Kunming mice were intraperitoneally injected with CP to establish an immunosuppression model and six mice were injected with the same volume of normal saline as a control. The 24 mice were randomly divided into four groups: manual acupuncture, 2 Hz EA treatment, 100 Hz EA treatment and alternating 2/100 Hz EA treatment. After EA treatment for 3 days, immune response, natural killer (NK) cell toxicity and the expression of cytokines and DREAM/NF-κB were assessed.

RESULTS

EA treatment, especially at alternating 2/100 Hz frequency, improved spleen and thymus indices, increased lactate dehydrogenase and acid phosphatase levels, promoted concanavalin A- and lipopolysaccharide-induced splenocyte proliferation, increased NK cell toxicity and ameliorated CP-induced immunosuppression in mice. Additionally, 2/100 Hz EA treatment increased interleukin (IL)-2, IL-6, IL-12, tumour necrosis factor-α and interferon-γ levels and decreased IL-10 levels in CP-induced immunosuppressed mice. Finally, it was found that 2/100 Hz EA treatment increased p-IκBα and NF-κB expression and decreased DREAM and IκBα expression, suggesting that this treatment activates the NF-κB signalling pathway.

CONCLUSION

2/100 Hz EA treatment might be an effective way to enhance immune responses in CP-induced immunosuppressed mice.

Efficacy of different-frequency TEAS on acute pain after the total knee arthroplasty: a study protocol for a parallel group randomized trial

BACKGROUND

Total knee arthroplasty (TKA) is an optimal option for patients with middle-to-end-stage knee osteoarthritis. However, the management of postoperative acute pain remains inefficient. Transcutaneous electrical acupoint stimulation (TEAS) is a nonpharmacological method to manage postoperative acute pain. Different frequencies of TEAS have been tested using varying parameters, but the optimal analgesic frequency remains controversial. The aim of this study was to explore the optimal analgesic frequency of TEAS for treating acute pain after the primary unilateral TKA.

METHODS/DESIGN

This is a double-blind, randomized controlled trial. A total of 156 patients are randomly assigned to: G1, 5 Hz TEAS; G2, 100 Hz TEAS; G3, mixed TEAS (alternative use of daily 5 Hz and 100 Hz TEAS) and G4, placebo TEAS. In the G1, G2 and G3 groups, TEAS is conducted at acupoints SP9 and GB34 of the leg that was operated on (at a wave of continuous, balanced and asymmetrical biphasic square, with a pulse width of 200 μs, and a strong but comfortable current) for 30 min prior to a 30-min rehabilitation session per day for 2 weeks. In G4 group, TEAS is delivered at a strong but comfortable current for 30 s, then the current is gradually decreased to none over the next 15 s. The primary outcomes are measured before surgery, at baseline (POD 3, before TEAS intervention), week 1 and 2 after TEAS intervention with the Numeric Pain Rating Scale and The American Knee Society Score. The secondary outcomes include: (1) Active range of motion of the knee that was operated on; (2) Surface electromyography of both quadriceps; (3) Modified 30-s sit to stand test; (4) Additional usage of analgesia; and (5) SF-36. The additional outcomes include: (1) Patients' satisfaction rate; (2) Patient's expectation rate; and (3) Incidence of analgesia-related side effects. To test the blinding of participants and assessors, they are asked to guess whether the subjects received active or placebo TEAS within 5 min after the latest intervention. The safety and financial cost of TEAS are assessed.

DISCUSSION

Mixed TEAS has more favorable effect on acute pain control than the placebo or 5 Hz or 100 Hz TEAS.

TRIAL REGISTRATION

ChiCTR1800016347 . Date of registration was 26 May 2018. Retrospectively registered.

Transcutaneous electrical acupoint stimulation for post-traumatic stress disorder: Assessor-blinded, randomized controlled study

AIM

Transcutaneous electrical acupoint stimulation (TEAS) has the potential to alleviate post-traumatic stress disorder (PTSD). The purpose of this study was to determine whether adding TEAS to sertraline or cognitive behavioral therapy (CBT) could improve the anti-PTSD efficacy.

METHODS

In this randomized controlled trial, 240 PTSD patients (60 in each group) were assigned to receive simulated TEAS combined with sertraline (group A) or with CBT (group B), active TEAS combined with CBT (group C), or active TEAS combined with CBT plus sertraline (group D) for 12 weeks. The outcomes were measured using the Clinician-Administered PTSD Scale, PTSD Check List-Civilian Version, and 17-item Hamilton Rating Scale for Depression.

RESULTS

While PTSD symptoms reduced over time in all patients, groups C and D had markedly greater improvement in both PTSD and depressive measures than groups A and B in all post-baseline measurement points, with moderate to very large effect sizes of 0.484-2.244. Groups C and D also had a significantly higher rate than groups A and B on clinical response (85.0% and 95.0% vs 63.3% and 60.0%, P < 0.001) and on remission (15.0% and 25.0% vs 3.3% and 1.7%, P < 0.001). The incidence of adverse events was similar between groups A and D and between groups B and C.

CONCLUSIONS

Additional TEAS augments the anti-PTSD and antidepressant efficacy of antidepressants or CBT, without increasing the incidence of adverse effects. TEAS could serve as an effective intervention for PTSD and comorbid depression. This trial was registered with www.chictr.org (no.: ChiCTR1800017255).

Analgesic efficacy of laser acupuncture and electroacupuncture in cats undergoing ovariohysterectomy

The aim of this study was to compare the effects of laser acupuncture and electroacupuncture on postoperative pain and analgesic requirements in cats. In a prospective, randomized and blinded clinical study, thirty cats undergoing ovariohysterectomy were sedated with intramuscular (IM) ketamine (5 mg/kg), midazolam (0.5 mg/kg), and tramadol (2 mg/ kg). Before the induction of anesthesia, the animals were randomly distributed into three groups of ten cats each: LA: bilateral Stomach 36 (ST-36) and Spleen 6 (SP-6) acupoints were stimulated with an infrared laser; EA: bilateral ST-36 and SP-6 acupoints were stimulated with an electrical stimulus; Control: no acupuncture was applied. Postoperative analgesia was evaluated in the first 24 hr post-extubation using the Interactive Visual Analogue Scale and UNESP-Botucatu Multidimensional Composite Pain Scale. Rescue analgesia was provided with IM tramadol (2 mg/kg), and the pain scores were reassessed 30 min after the rescue intervention. If the analgesia remained insufficient, meloxicam (0.2 mg/kg IM, single dose) was administered. Data were analyzed using t-tests, the Mann-Whitney U test, and Friedman test. P<0.05 was considered significant. The pain scores did not significantly differ between the treatment groups at any time point (P>0.05). The prevalence of rescue analgesia was significantly higher in the Control group than in the LA and EA groups (P=0.033). Preoperative laser and electroacupuncture reduced the need for rescue analgesia during the first 24 hr after ovariohysterectomy.

A Mechanism-Based Approach to Physical Therapist Management of Pain

Pain reduction is a primary goal of physical therapy for patients who present with acute or persistent pain conditions. The purpose of this review is to describe a mechanism-based approach to physical therapy pain management. It is increasingly clear that patients need to be evaluated for changes in peripheral tissues and nociceptors, neuropathic pain signs and symptoms, reduced central inhibition and enhanced central excitability, psychosocial factors, and alterations of the movement system. In this Perspective, 5 categories of pain mechanisms (nociceptive, central, neuropathic, psychosocial, and movement system) are defined, and principles on how to evaluate signs and symptoms for each mechanism are provided. In addition, the underlying mechanisms targeted by common physical therapist treatments and how they affect each of the 5 categories are described. Several different mechanisms can simultaneously contribute to a patient's pain; alternatively, 1 or 2 primary mechanisms may cause a patient's pain. Further, within a single pain mechanism, there are likely many possible subgroups. For example, reduced central inhibition does not necessarily correlate with enhanced central excitability. To individualize care, common physical therapist interventions, such as education, exercise, manual therapy, and transcutaneous electrical nerve stimulation, can be used to target specific pain mechanisms. Although the evidence elucidating these pain mechanisms will continue to evolve, the approach outlined here provides a conceptual framework for applying new knowledge as advances are made.

Electroacupuncture pretreatment with different waveforms prevents brain injury in rats subjected to cecal ligation and puncture via inhibiting microglial activation, and attenuating inflammation, oxidative stress and apoptosis

Sepsis is associated with high morbidity and mortality. This study was to investigate the protective effects of electroacupuncture (EA) pretreatment with different waveforms on septic brain injury in rats and its mechanism. Male Sprague-Dawley rats were pretreated by EA with different waveforms (continuous wave, dilatational wave, or intermittent wave) at Baihui (GV20) and Tsusanli (ST36) acupoints for 30min, and underwent cecal ligation and puncture (CLP) or sham operation. The results showed that EA pretreatment with different waveforms improved survival rate, attenuated encephaledema, brain injury, neuronal apoptosis and cognitive dysfunction, and preserved blood-brain barrier (BBB). EA pretreatment decreased the production of tumor necrosis factor(TNF)-α, interleukin(IL)-6, malondialdehyde (MDA), and increased the activity of superoxide dismutase (SOD) and catalase (CAT) in serum and hippocampus at 48h after sham or CLP operation. Additionally, EA pretreatment downregulated the expressions of toll-like receptor-4 (TLR-4), nuclear factor-kappa B (NF-κB) and ionized calcium binding adaptor molecule 1(Iba 1). The effect of dilatational wave was the most significant, followed by intermittent wave, and continuous wave was relatively poor. In conclusion, our results demonstrate that EA pretreatment with three waveforms alleviates sepsis-induced brain injury by inhibition of microglial activation and attenuation of inflammation, oxidative stress and apoptosis. These findings suggest that EA pretreatment with dilatational wave at Baihui and Tsusanli acupoints might be a promising therapeutic strategy for relieving septic brain injury.

Electroacupuncture in conscious free-moving mice reduces pain by ameliorating peripheral and central nociceptive mechanisms

Integrative approaches such as electroacupuncture, devoid of drug effects are gaining prominence for treating pain. Understanding the mechanisms of electroacupuncture induced analgesia would benefit chronic pain conditions such as sickle cell disease (SCD), for which patients may require opioid analgesics throughout life. Mouse models are instructive in developing a mechanistic understanding of pain, but the anesthesia/restraint required to administer electroacupuncture may alter the underlying mechanisms. To overcome these limitations, we developed a method to perform electroacupuncture in conscious, freely moving, unrestrained mice. Using this technique we demonstrate a significant analgesic effect in transgenic mouse models of SCD and cancer as well as complete Freund's adjuvant-induced pain. We demonstrate a comprehensive antinociceptive effect on mechanical, cold and deep tissue hyperalagesia in both genders. Interestingly, individual mice showed a variable response to electroacupuncture, categorized into high-, moderate-, and non-responders. Mechanistically, electroacupuncture significantly ameliorated inflammatory and nociceptive mediators both peripherally and centrally in sickle mice correlative to the antinociceptive response. Application of sub-optimal doses of morphine in electroacupuncture-treated moderate-responders produced equivalent antinociception as obtained in high-responders. Electroacupuncture in conscious freely moving mice offers an effective approach to develop a mechanism-based understanding of analgesia devoid of the influence of anesthetics or restraints.

Electroacupuncture Treatment Alleviates Central Poststroke Pain by Inhibiting Brain Neuronal Apoptosis and Aberrant Astrocyte Activation

Electroacupuncture (EA) is reported to effectively relieve the central poststroke pain (CPSP). However, the underlying mechanism remains unclear. The present study investigated the detailed mechanisms of action of EA treatment at different frequencies for CPSP. A CPSP model was established with a single collagenase injection to the left ventral posterolateral nucleus of the thalamus. The EA-treated groups then received EA treatment at frequency of 2, 2/15, or 15 Hz for 30 min daily for five days. The pain-related behavioral responses, neuronal apoptosis, glial activation, and the expression of pain signal transmission-related factors (β-catenin, COX-2, and NK-1R) were assessed using behavioral tests, Nissl staining, TUNEL staining, and immunohistochemical staining, respectively. The low-frequency EA treatment significantly (1) reduced brain tissue damage and hematoma sizes and (2) inhibited neuronal apoptosis, thereby exerting abirritative effects. Meanwhile, the high-frequency EA treatment induced a greater inhibition of the aberrant astrocyte activation, accompanied by the downregulation of the expressions of COX-2, β-catenin, and subsequently NK-1R, thereby alleviating inflammation and producing strong analgesic effects. Together, these findings suggest that CPSP is closely related to pathological changes of the neocortex and hippocampus. EA treatments at different frequencies may exert abirritative effects by inhibiting brain neuronal apoptosis and aberrant astrocyte activation in the brain.

Electroacupuncture analgesia with different frequencies is mediated via different opioid pathways in acute visceral hyperalgesia rats

AIMS

To investigate the efficacy of electroacupuncture (EA) alleviation of acute visceral hyperalgesia, the frequency dependence of this efficacy, and the difference in endogenous opioid pathways as underlying mechanism explaining the frequency dependence.

MAIN METHODS

A visceral hyperalgesia model was established by colorectal instillation of 2% acetic acid (AA) in adult rats. EA treatment at 2Hz, 100Hz, 2/100Hz and sham EA were performed at two bilateral acupoints, ST-36 and ST-37, in the hind-limbs. Naloxone (NLX, 2mg/kg) was administered intraperitoneally 5min before the application of EA. The visceral sensation was quantified by scores of abdominal withdrawal reflex (AWR) and values of rectus abdominis electromyograms (EMGs) in response to colorectal distension (CRD).

KEY FINDINGS

Acute visceral hyperalgesia was produced by instillation of AA. The hyperalgesia reached the peak at 2h, and maintained steadily for >6h. EA treatment at 2Hz, 100Hz and 2/100Hz attenuated the acute hyperalgesia, and the attenuation lasted for 2.5h, 2h and 3h, respectively. Sham EA produced no such effect. The analgesic potencies of EA treatment at 2Hz, 100Hz and 2/100Hz were completely blocked, almost not affected, and partially blocked by NLX. In the latter two frequencies, the analgesic durations were shortened to 1.5h and 2h, respectively.

SIGNIFICANCE

EA can alleviate acute visceral hyperalgesia. Effective EA analgesia at different frequencies are potentially mediated via different endogenous opioid pathways.

Preemptive Analgesic Effects of Transcutaneous Electrical Nerve Stimulation (TENS) on Postoperative Pain: A Randomized, Double-Blind, Placebo-Controlled Trial

Background

Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological analgesic method used to control different types of pain.

Objectives

The aim of this study was to evaluate the effects of preoperative TENS on post inguinal hernia repair pain.

Patients and Methods

This randomized, double-blind, placebo-controlled clinical trial was performed on 66 male patients with unilateral inguinal hernias who were admitted to the Shahid Beheshti hospital in Kashan, Iran, from April to October 2014. Participants were selected using a convenience sampling method and were assigned to intervention (n = 33) and control (n = 33) groups using permuted-block randomization. Patients in the intervention group were treated with TENS 1 hour before surgery, while the placebo was administered to patients in the control group. All of the patients underwent inguinal hernia repair by the Lichtenstein method, and pain intensity was evaluated at 2, 4, 6, and 12 hours after surgery using a visual analogue scale. Additionally, the amounts of analgesic administered by pump were calculated and compared between the two groups.

Results

The mean estimated postoperative pain intensity was 6.21 ± 1.63 in the intervention group and 5.45 ± 1.82 in the control group (P = 0.08). In the intervention group pain intensity at 2 and 4 hours after surgery were 3.54 ± 1.48 and 5.12 ± 1.41 (P < 0.001), respectively. In the control group these values were 4.0±1.5 and 4.76 ± 1.39 (P = 0.04), respectively. No significant differences were observed in mean pain intensities at 6 and 12 hours.

Conclusions

TENS can reduce postoperative pain in the early hours after inguinal hernia repair surgery.

Involvement of hippocampal acetylcholinergic receptors in electroacupuncture analgesia in neuropathic pain rats

BACKGROUND

Cumulating evidence has shown a close correlation between electroacupuncture stimulation (EAS) frequency-specific analgesic effect and central opioid peptides. However, the actions of hippocampal acetylcholinergic receptors have not been determined. This study aims to observe the effect of different frequencies of EAS on the expression of hippocampal muscarinic and nicotinic acetylcholinergic receptors (mAChRs, nAChRs) in neuropathic pain rats for revealing their relationship.

METHODS

Forty male Wistar rats were randomly and equally divided into sham, CCI model, 2, 2/15 and 100 HzEA groups. The neuropathic pain model was established by ligature of the left sciatic nerve to induce chronic constriction injury (CCI). EAS was applied to bilateral Zusanli (ST36) and Yanglingquan (GB34) for 30 min, once daily for 14 days except weekends. The mechanical pain thresholds (withdrawal latencies, PWLs) of bilateral hindpaws were measured. The expression levels of hippocampal M1 and M2 mAChR, and α4 and β2 nAChR genes and proteins were detected by quantitative RT-PCR and Western blot, separately. The involvement of mAChR and nAChR in the analgesic effect of EAS was confirmed by intra-hippocampal microinjection of M1mAChR antagonist (Pirenzepine) and α4β2 nAChR antagonist (dihydro-beta-erythroidine) respectively.

RESULTS

Following EAS, the CCI-induced increase of difference values of bilateral PWLs on day 6 and 14 was significantly reduced (P < 0.05), with 2/15 Hz being greater than 100 Hz EAS on day 14 (P < 0.05). After 2 weeks' EAS, the decreased expression levels of M1 mAChR mRNA of both 2 and 2/15 Hz groups and M1 mAChR protein of the three EAS groups, α4 AChR mRNA of the 2/15 Hz group and β2 nAChR protein of the three EAS groups were considerably increased (P < 0.05), suggesting an involvement of M1 mAChR and β2 nAChR proteins in EAS-induced pain relief. No significant changes were found in the expression of M2 mAChR mRNA and protein, α4 nAChR protein and β2 nAChR mRNA after CCI and EAS (P > 0.05). The analgesic effect of EAS was abolished by intra-hippocampal microinjection of M1mAChR and α4β2 nAChR antagonists respectively.

CONCLUSIONS

EAS of ST36-GB34 produces a cumulative analgesic effect in neuropathic pain rats, which is frequency-dependent and probably mediated by hippocampal M1 mAChR and β2 nAChR proteins.

Endogenous opiates and behavior: 2014

This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants). This paper is the thirty-seventh consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2014 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (endogenous opioids and receptors), and the roles of these opioid peptides and receptors in pain and analgesia (pain and analgesia); stress and social status (human studies); tolerance and dependence (opioid mediation of other analgesic responses); learning and memory (stress and social status); eating and drinking (stress-induced analgesia); alcohol and drugs of abuse (emotional responses in opioid-mediated behaviors); sexual activity and hormones, pregnancy, development and endocrinology (opioid involvement in stress response regulation); mental illness and mood (tolerance and dependence); seizures and neurologic disorders (learning and memory); electrical-related activity and neurophysiology (opiates and conditioned place preferences (CPP)); general activity and locomotion (eating and drinking); gastrointestinal, renal and hepatic functions (alcohol and drugs of abuse); cardiovascular responses (opiates and ethanol); respiration and thermoregulation (opiates and THC); and immunological responses (opiates and stimulants).

Effects of Transcutaneous Electrical Nerve Stimulation on Rats with the Third Lumbar Vertebrae Transverse Process Syndrome

Objective

To investigate the analgesic and anti-inflammatory effects of transcutaneous electrical nerve stimulation (TENS) at local or distant acupuncture points in a rat model of the third lumbar vertebrae transverse process syndrome.

Methods

Forty Sprague–Dawley rats were randomly divided into control, model, model plus local acupuncture point stimulation at BL23 (model+LAS) and model plus distant acupuncture point stimulation at ST36 (model+DAS) groups. All rats except controls underwent surgical third lumbar vertebrae transverse process syndrome modelling on day 2. Thereafter, rats in the model+LAS and model+DAS groups were treated daily with TENS for a total of six treatments (2/100 Hz, 30 min/day) from day 16 to day 29. Thermal pain thresholds were measured once a week during treatment and were continued until day 57, when local muscle tissue was sampled for RT-PCR and histopathological examination after haematoxylin and eosin staining. mRNA expression of interleukin-1 β (IL-1β), tumour necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) was determined.

Results

Thermal pain thresholds of all model rats decreased relative to the control group. Both LAS and DAS significantly increased the thermal pain threshold at all but one point during the treatment period. Histopathological assessment revealed that the local muscle tissues around the third lumbar vertebrae transverse process recovered to some degree in both the model+LAS and model+DAS groups; however, LAS appeared to have a greater effect. mRNA expression of IL-1β, TNF-α and iNOS in the local muscle tissues was increased after modelling and attenuated in both model+LAS and model+DAS groups. The beneficial effect was greater after LAS than after DAS.

Conclusions

TENS at both local (BL23) and distant (ST36) acupuncture points had a pain-relieving effect in rats with the third lumbar vertebrae transverse process syndrome, and LAS appeared to have greater anti-inflammatory and analgesic effects than DAS.

Trial Registration Number

09073.

Effects of Electroacupuncture with Dominant Frequency at SP 6 and ST 36 Based on Meridian Theory on Pain-Depression Dyad in Rats

Epidemic investigations reveal an intimate interrelationship between pain and depression. The effect of electroacupuncture (EA) on pain or depression has been demonstrated individually, but its effect on pain-depression dyad is unknown. Our study aimed to screen a dominant EA frequency on pain-depression dyad and determine the validity of acupoint selection based on meridian theory. The pain-depression dyad rat model was induced by reserpine and treated using EA with different frequencies at identical acupoints to extract a dominant frequency and then administrated dominant-frequency EA at different acupoints in the above models. Paw withdrawal latency (PWL), emotional behavior of elevated zero maze (EZM) test, and open field (OF) test were conducted. We found that 100 Hz EA at Zusanli (ST 36) and Sanyinjiao (SP 6) (classical acupoints for spleen-deficiency syndrome) were the most effective in improving PWL, travelling distance in the EZM, and maximum velocity in OF compared to EA with other frequencies; ST 36 and SP 6 were proved more effective than other acupoints beyond the meridian theory and nonacupoints under the same administration of EA. Therefore, we concluded that 100 Hz is the dominant frequency for treating the pain-depression dyad with EA, and acupoints on spleen and stomach meridians are preferable choices.

Efficacy and safety of transcutaneous electrical acupoint stimulation to treat muscle spasticity following brain injury: a double-blinded, multicenter, randomized controlled trial

Objective

This study was aimed at evaluating the clinical efficacy and safety of transcutaneous electrical acupoint stimulation (TEAS) to treat muscle spasticity after brain injury (Chinese Clinical Trial Registry: ChiCTR-TRC-11001310).

Methods

A total of 60 patients with muscle spasticity after brain injury were randomized to the following 3 groups: 100, 2, and 0 Hz (sham) TEAS. The acupoints Hegu (LI4)—Yuji (LU10) and Zusanli (ST36)—Chengshan (BL57) on the injured side were stimulated at 0, 2, or 100 Hz, 5 times per week for 4 weeks. The patients were followed up for 1 and 2 months after the treatments. The effects of the treatments on muscle spasticity at the wrist, thumb, the other 4 fingers, elbow, shoulder, knee, and ankle were evaluated by the Modified Ashworth Scale, and the effects on disability were assessed by the Disability Assessment Scale. The walking capability was evaluated by the Holden functional ambulation classification score. The overall performance was assessed by the Global Assessment Scale score and the improved Barthel Index. The safety of the treatments administered was also monitored.

Results

The wrist spasticity was significantly reduced from baseline at weeks 2, 3, and 4 of treatment and at the 1- and 2-month follow-up visits in the 100 Hz group (P < 0.01). Compared with 2 Hz or sham TEAS, 100 Hz TEAS decreased wrist spasticity at weeks 2, 3, and 4 of treatment and 1 month after treatment (P < 0.001). The other endpoints were not affected by the treatments. No treatment-emergent adverse events were reported during treatments and follow-up visits.

Conclusions

TEAS appears to be a safe and effective therapy to relieve muscle spasticity after brain injury, although large-scale studies are required to further verify the findings.

Trial Registration

Chinese Clinical Trial Registry ChiCTR-TRC-11001310 http://www.chictr.org

Genomewide analysis of rat periaqueductal gray-dorsal horn reveals time-, region- and frequency-specific mRNA expression changes in response to electroacupuncture stimulation

Electroacupuncture (EA) has been widely applied for illness prevention, treatment or rehabilitation in the clinic, especially for pain management. However, the molecular events that induce these changes remain largely uncharacterized. The periaqueductal gray (PAG) and the spinal dorsal horn (DH) have been verified as two critical regions in the response to EA stimulation in EA analgesia. In this study, a genetic screen was conducted to delineate the gene expression profile in the PAG-DH regions of rats to explore the molecular events of the analgesic effect induced by low-frequency (2-Hz) and high-frequency (100-Hz) EAs. Microarray analysis at two different time points after EA stimulation revealed time-, region- and frequency-specific gene expression changes. These expression differences suggested that modulation of neural-immune interaction in the central nervous system played an important role during EA analgesia. Furthermore, low-frequency EA could regulate gene expression to a greater degree than high-frequency EA. Altogether, the present study offers, for the first time, a characterized transcriptional response pattern in the PAG-DH regions followed by EA stimulation and, thus, provides a solid experimental framework for future in-depth analysis of the mechanisms underlying EA-induced effects.

Effects of Governor Vessel electroacupuncture on the systematic expressions of NTFs in spinal cord transected rats

This study evaluated the effects Governor Vessel electroacupuncture (GVEA) on the systematic regulation of neurotrophic factors (NTFs) in the spinal segments caudal (CSS) to the site of transection in rats subjected to spinal cord transection (SCT). Using RT-PCR, we amazingly found the gene expressions of NGF, IGF-1, FGF-2, CNTF, PDGF, TGF-β1, TrkA, TrkB and TrkC were downregulated following GVEA treatment. However, the number of GAP-43 and Synaptophysin profiles in the CSS in the GVEA rats showed a significant increase, compared with non-EA animals, although both the 5-HT and corticospinal fibers have no statistical differences in the CSS. Simultaneously, there was significant recovery in hindlimb locomotor and sensory functions after GVEA treatment. Therefore, these findings challenge the past view that GVEA promotes functional restoration, which is linking to the up-regulation of NTFs in rats subjected to SCT. The present findings may give some novel indication on the mechanism of acupuncture for the treatment of SCI.