Different Frequencies Of Electroacupuncture Research Articles

Map activation of various brain regions using different frequencies of electroacupuncture ST36, utilizing the Fos-CreER strategy

Objective: Electroacupuncture (EA) is an alternative treatment option for pain. Different frequencies of EA have different pain-relieving effects; however, the central mechanism is still not well understood. Methods: The FosTRAP:Ai9 mice were divided into three groups (sham, 2 Hz, and 100 Hz). The mice were intraperitoneally injected with 4-hydroxytamoxifen (4-OHT) immediately after EA at Zusanli (ST36) for 30 min to record the activated neurons. One week later, the mice were sacrificed, and the number of TRAP-treated neurons activated by EA in the thalamus, amygdala, cortex, and hypothalamus was determined. Results: In the cortex, 2 Hz EA activated more TRAP-treated neurons than 100 Hz EA did in the cingulate cortex area 1 (Cg1) and primary somatosensory cortex (S1), and 2 Hz and 100 Hz EAs did not differ from sham EA. TRAP-treated neurons activated by 2 Hz EA were upregulated in the insular cortex (IC) and secondary somatosensory cortex (S2) compared with those activated by 100 Hz and sham EA. In the thalamus, the number of TRAP-treated neurons activated by 2 Hz EA was elevated in the paraventricular thalamic nucleus (PV) compared with those activated by sham EA. In the ventrolateral thalamic nucleus (VL), the number of TRAP-treated neurons activated by 2 Hz EA was significantly upregulated compared with those activated by 100 Hz EA, and sham EA showed no difference compared to 2 Hz EA or 100 Hz EA. TRAP-treated neurons were more frequently activated in the ventral posterolateral thalamic nucleus (VPL) by 2 Hz EA than by 100 Hz or sham EA. Conclusion: Low-frequency EA ST36 effectively activates neurons in the Cg1, S1, S2, IC, VPL, PV, and VL. The enhanced excitability of the aforementioned nuclei induced by low-frequency EA may be related to its superior efficacy in the treatment of neuropathological pain.

Efficacy of electroacupuncture with different frequencies in the treatment of chemotherapy-induced peripheral neuropathy: A study protocol for a randomized controlled trial.

IntroductionChemotherapy-induced peripheral neuropathy (CIPN) is a common complication in patients with cancer during chemotherapy. It mainly leads to severe numbness of the hands and feet and causes great pain in patients. Electroacupuncture (EA) is considered to be beneficial in improving peripheral neuropathy and relieving numbness of the hands and feet. This trial aims to evaluate the therapeutic effect of different frequencies of EA on CIPN in patients with cancer.Methods and analysisThis study is a randomized controlled trial. In total, 160 eligible CIPN patients are randomly assigned to the 2 Hz EA group, 100 Hz EA group, 2/100 Hz EA group, and control group in the ratio of 1:1:1:1. All patients in the EA treatment groups receive treatment with EA three times a week for 4 weeks and following up for 4 weeks. The patients in the control group are given Mecobalamin (MeCbl) tablets orally, one tablet at a time, three times a day, for 4 weeks, and following up for 4 weeks. The primary outcome measures are the participant neurotoxicity questionnaire (PNQ) and the peripheral neurotoxicity assessment rating (NCI CTCAE V5.0). Secondary outcomes are the quality of life scale (EORTC QLQ-C30) and the measurement of peripheral nerve conduction velocity (NCV). The results are evaluated at baseline, post-treatment phase, and following up for 4 weeks. All major analyses are based on the intention to treat principle.Ethics/disseminationThis protocol was approved by the Medical Ethics Committee of the Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital) on 7 December 2021. The license number is IRB-2021-458. This study provides clinical efficacy data of different frequencies of EA in the treatment of CIPN. The results help to prove whether EA is an effective therapy for CIPN and optimize the frequency of EA for CIPN. The results of this study are shared with health care professionals, the public, and relevant organizations through the publication of manuscripts and conference reports.Trial registration numberChiCTR2100054458.

Acupuncture and Related Techniques for Pain Relief and Treatment of Heroin Addiction: Mechanisms and Clinical Application.

A neurochemical hypothesis of acupuncture analgesia suggests that the pain relief effect of acupuncture is primarily due to activation of a central endorphin system. It has been shown that the primary afferent sensory fibers, a mesolymbic neural circuit, and a descending inhibitory pathway are critical in acupuncture analgesia. The therapeutic effects of electroacupuncture (EA) and related techniques, such as transcutaneous electroacupoint stimulation (TEAS), are frequency-dependent: different frequencies of EA activate different brain regions and release different neuropeptides. EA and TEAS have been used successfully to treat heroin addiction. Activation of endorphin gene expression and release by TEAS can explain the dramatic attenuation of withdrawal syndrome and prolongation of retention time during and after detoxification treatment in patients who are addicted to heroin. However, repeated EA at high intensity should be avoided because it can induce a gradual loss of the analgesic effect. Opioid-receptor desensitization occurs and is manifested as decreased ligand-binding affinity and second-messenger detachment. Repeated large doses of morphine induce morphine tolerance. Cross-tolerance between morphine and EA suggests similar underlying mechanisms. Recent studies have demonstrated that excessive activation of cholecystokinin (CCK), an antiopioid peptide, appears to be responsible. CCK-receptor subtype B (CCKBR) and opioid μ-receptor are co-expressed in the dorsal-horn neurons. Activation of CCKBR promotes formation of heteromerization of morphine-receptor and CCKBR. Interaction of the third transmembrane domain between the 2 receptors resulted in the reduced binding affinity of the opioid receptor.

Effect of Different Frequencies of Electroacupuncture on Post-Stroke Dysphagia in Mice.

The aim of this study was to determine the optimum frequency of electroacupuncture (EA) for the treatment of dysphagia after stroke. Male C57BL/6J mice were randomly divided into five groups: normal, model, 2Hz, 50Hz, and 100Hz groups. All mice received a photochemical ischemia, except the normal group. The EA parameters were 1mA for 15min, with different frequencies (2, 50, and 100Hz) applied. After a three day treatment, neuronal activation was detected by the expression of c-Fos. A multi-channel electrophysiological technique was used to assess the discharge of contralateral neurons and the neuron types in each group. The concentration of brain-derived neurotrophic factor (BDNF) in the contralateral neurons was also examined. In addition, the dysfunction of swallowing in mice was calculated according to the lick counts and the lick-lick interval within a certain period of time. The number of c-Fos neurons (P < 0.05) and the expression of BDNF (P < 0.05) increased after the 2Hz EA treatment. The total frequency of neuron discharge in the 2Hz group increased compared with the model group (P < 0.05). The pattern of sorted neuron populations was similar between the normal and 2Hz groups. Consistent with these results, the lick counts increased (P < 0.05) and the lick-lick interval decreased after the 2Hz EA treatment, which indicated a functional improvement in swallowing. These results indicated that the 2Hz EA treatment had a good effect on dysphagia after stroke.

Effects of electroacupuncture frequencies on chronic low back pain in older adults: triple-blind, 12-months protocol for a randomized controlled trial

BackgroundLow back pain (LBP) is the most frequent complaint in clinical practice. Electroacupuncture treatment may be effective; however, the supporting evidence is still limited, especially in older adults.ObjectiveThe current study is a randomized controlled trial that aims to evaluate the clinical efficacy of electroacupuncture in older adults with LBP.MethodsA five-arm randomized controlled trial with patients and evaluators blinded to the group allocation. A total of 125 participants with non-specific LBP will be randomly assigned into one of five groups: three electroacupuncture groups (low, high, and alternating frequency); one control group; and one placebo group. The electroacupuncture will be applied twice a week (30 min per session) for five weeks. The primary clinical outcome measure will be pain intensity. The secondary outcomes include: quality of pain; physical functioning; perceived overall effect; emotional functionality; patient satisfaction; and psychosocial factors. Patients will be evaluated before the first session, immediately after the last, and followed up after six and 12 months to check the medium- and long-term effects.DiscussionAlthough electroacupuncture is increasingly used to treat LBP, there is no guidance regarding the parameters used, which leads to inconsistent results. Thus, the effect of electroacupuncture (EA) on LBP remains controversial and requires more studies, especially in the older adult population.ConclusionThis is the first randomized controlled trial to evaluate the efficacy of different frequencies of electroacupuncture for treating chronic LBP in older adults. This study will provide evidence on the effectiveness of electroacupuncture as an alternative treatment method for LBP and will entail wider debate about an appropriate acupuncture intervention in this population.Trial registrationClinicaltrials.gov, NCT03802045. Registered on 14 January 2019.

Effect of electroacupuncture with different frequencies on hindlimb locomotor function and expression of LC3, Beclin 1 and cleaved Caspase-3 proteins in spinal cord injury rats

To investigate the effect of different frequencies of electroacupuncture (EA) on motor function and expression of autophagy-related proteins microtubule-associated protein light chain 3 (LC3), etc. in spinal cord injury (SCI) rats, so as to reveal its underlying mechanisms and provide a reference for clinical application. A total of 100 male SD rats were randomly divided into sham control, model, 2 Hz-EA, 100 Hz-EA and 2 Hz/100 Hz-EA groups(n=20 in each group). EA (2 Hz, 100 Hz or 2 Hz/100 Hz, 0.4-0.5-0.6 mA increased by 0.1 mA every10 min) was applied to "HuatuoJiaji" (EX-HN1, T9 and T11) for 30 min, once a day for 7 days. The rat's hindlimb motor function was assessed by using Basso, Beattie and Bresnahan(BBB) locomotor rating scale, inclined plane test and plantar imprinting test, separately. The histological changes and neuronal apoptosis of the spinal cord tissue were observed by Fluoro-Jade B (FJB) and Nissl staining, respectively. The expression of LC3, Beclin 1 and cleaved Caspase-3 proteins in the spinal cord was detected by Western blot. After modeling, the BBB scores and the angles of inclined plane on day 1, 3 and 7 were significantly decreased (P<0.001), and the number of FJB positive cells, and the expression levels of Beclin 1 and cleaved Caspase-3 proteins were considerably increased in the model group compared with the sham control group (P<0.001, P<0.05). After EA intervention, the BBB score and the angles of inclined plate on day 3 in the 2 Hz/100 Hz-EA group (rather than in the 2 Hz- and 100 Hz-EA groups), the BBB score and the angles of inclined plate on day 7 in both 2 Hz/100 Hz and 100 Hz-EA groups(rather than in the 2 Hz-EA group), and the expression levels of Beclin 1 and LC3-Ⅱ/Ⅰ in both 2 Hz/100 Hz and 100 Hz-EA groups (rather than in the 2 Hz-EA group) on day 7 were obviously increased (P<0.001, P<0.01, P<0.05), while the number of FJB-positive neurons in the 3 EA groups, and the expression of cleaved Caspase-3 protein in both 2 Hz/100 Hz and 100 Hz-EA groups and the LC3-Ⅱ/Ⅰ in the 2 Hz-EA group were obviously decreased relevant to the model group (P<0.001, P<0.05). The expression of Beclin 1 in the 100 Hz-EA group was obviously decreased relevant to the 2 Hz/100 Hz-EA group (P<0.05) .Nissl staining displayed appearance of cavities and fuzzy shape of Nissl bodies with light coloration in the injured spinal cord of model group, which was milder in both 2 Hz/100 Hz-EA and 100 Hz-EA groups. Plantar imprinting tests showed dragging gait prints in the model group due to disability in movement, and relatively distinct foot imprints in both 2 Hz/100 Hz and 100 Hz-EA groups. Both 100 Hz and 2 Hz/100 Hz-EA can effectively promote the recovery of hindlimb locomotor function of SCI rats, which may be related to its function in promoting autophagy of damaged nerve cells and in reducing neuronal apoptosis.

The effect of different frequencies of electroacupuncture on BDNF and NGF expression in the hippocampal CA3 area of the ischemic hemisphere in cerebral ischemic rats.

ObjectiveThe aim of this study was to observe the effects of different frequencies of electroacupuncture (EA) on expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the hippocampal CA3 region of cerebral ischemic rats.MethodsMiddle cerebral artery occlusion was successfully introduced to simulate cerebral infarction in 48 healthy male Sprague–Dawley rats. Totally, 48 rats were randomly divided into three groups: the control group, the EA 5-Hz group, and the EA 50-Hz group, 16 in each group. The rats in the control group were placed in an ordinary cage and fed normally without any treatment. EA treatment was given at a certain frequency 24 hours after surgery in the EA 5-Hz group and EA 50-Hz group. Morris water maze test was used to measure the learning and memory abilities of rats in each group after 14-day treatment with EA. Immunohistochemical staining was used to detect the expression of BDNF- and NGF-positive cells in the ischemic hippocampal CA3 area of the rats.ResultsThe EA 5-Hz group and EA 50-Hz group had significantly improved learning and memory ability compared with the control group according to Morris water maze findings (P<0.05). The number of BDNF- and NGF-positive cells in the hippocampal CA3 region of the ischemic hemisphere in the 5-Hz group and 50-Hz EA group was significantly more than that in the control group after EA treatment (P<0.05), and the difference in the 50-Hz group was more obvious than that in the 5-Hz group. The difference was statistically significant (P<0.05).ConclusionEA stimulation of “Baihui” and “Dazhui” can promote the expression of BDNF and NGF in the hippocampal CA3 region of cerebral ischemic rats, and the 50-Hz EA stimulation effect is more obvious.

Stimulating Frequency-dependent Analgesic Effect of Electroacupuncture via Down-regulating Expression of VEGF in Dorsal Horns of Lumbar Spinal Cord in Post Herpetic Neuralgia Rats

To observe the effect of different frequencies of electroacupuncture (EA) stimulation on pain threshold (PT) and expression of vascular endothelial growth factor (VEGF) in dorsal horns (DHs) of the lumbar spinal cord in resiniferatoxin (RTX)-induced post-herpetic neuralgia (PHN) rats, so as to reveal its mechanism in alleviating PHN. Male SD rats were randomized into control, model, 2 Hz-EA, 15 Hz-EA, 100 Hz-EA and sham EA groups (n=16 in each). The PHN model was induced by a single intraperitoneal injection of RTX (250 μg/kg), and rats of the control group received intraperitoneal injection of the same dose of vehicle (10% Tween 80, 10% alcohol and 0.9% NaCl). Rats of EA treatment groups received EA stimulation (2 Hz, 15 Hz or 100 Hz, 1 mA) at the left "Huantiao" (GB 30) and "Yanglingquan" (GB 34) for 30 min, once every other day for 35 days, starting from 1 week after RTX injection. For sham control, acupuncture needles were inserted ipsilaterally into GB 30 and GB 34 for 30 min without electrical stimulation or manual needle manipulation. The mechanical allodynia was quantified with Von Frey filaments. The expression of mRNA and protein of VEGF in the DHs of lumbar spinal cord 4-6 segments (sampled under light microscope) was detected by quantitative polymerase chain reaction (qPCR) and Western blot, respectively. A single RTX injection gradually induced tactile allodynia (significant reduction of the mechanical PT) within 3 weeks relevant to the control group (P<0.01). EA applied to GB 30 and GB 34 at 2 Hz and 15 Hz, but not 100 Hz, significantly decreased the tactile allodynia after the treatment (2 Hz from 2 weeks on and 15 Hz from 3 weeks on) in RTX-treated rats (P<0.05). RTX administration increased the mRNA and protein expression of VEGF in the lumbar spinal cord compared with the control group (P<0. 05). Moreover, 2 Hz, but not 15 Hz and 100 Hz EA significantly reduced VEGF mRNA and protein expression(P<0.05). The expression of both VEGF mRNA and protein was negatively correlated with mechanical PT in RTX-induced PHN rats. EA at 2 Hz can significantly reduce VEGF expression in the lumbar spinal cord DHs of PHN rats, which is possibly in part related to its effect in alleviating the mechanical allodynia. Our study suggests that 2 Hz EA is the best stimulation frequency for relieving PHN.

TRPV1 is a Responding Channel for Acupuncture Manipulation in Mice Peripheral and Central Nerve System

Background/Aims: Acupuncture involves inserting a fine needle into a specific point, often called an acupoint, thereby initiating a therapeutic effect accompanied by phenomena such as soreness, heaviness, fullness, and numbness. Acupoints are characterized as points located in deep tissues with abundant sensory nerve terminals, which suggests that there is a strong relationship between acupoints and peripheral sensory afferents. In this study, we determined whether manual acupuncture (MA) or different frequencies of electroacupuncture (EA) share similar mechanisms for activating excitatory neurotransmission. Methods: We performed MA or EA at acupoint ST36 and we also used western blot and immunostaining techniques to determine neural changes at the peripheral dorsal root ganglion (DRG), spinal cord (SC), and somatosensory cortex (SSC) levels. Results: Our results show that either MA or EA at the ST36 acupoint significantly increased components of the TRPV1-related signaling pathway, such as pPKA, pPI3K, pPKC-pERK, and pAKT (but not pp38 or pJNK) at the peripheral DRG and central SC-SSC levels. Furthermore, excitatory phosphorylated N-methyl-D-aspartate receptor (pNMDA) and pCaMKIIα (but not pNR2B, pCaMKIIδ, or pCaMKIIγ) also increased. These molecules could not increase in the DRG and SC-SSC of TRPV1^–/–mice. Conclusion: Our data demonstrates that both MA and EA can activate excitatory signals in either peripheral or central levels. We also define that TRPV1 is crucial for an acupuncture effect and then initiate excitatory pNR1-pCaMKII pathway, at peripheral DRG and central SC-SSC level. We suggest that the TRPV1 signaling pathway is highly correlated to Acupuncture effect that implies the real clinical significance.

Effects and mechanisms of different frequencies of electroacupuncture for learning and memory ability of Alzheimer's rats

To observe the effects of different frequencies of electroacupuncture (EA) at "Baihui (GV 20)" and "Shenshu(BL 23)" for the learning and memory ability as well as glycogen synthase kinase-3β (GSK-3β) and growth associated protein-43 (GAP-43) in hippocampal tissue of rats with Alzheimer's disease(AD), so as to explore the mechanism of different frequencies of EA for the prevention and treatment of AD. One hundred and twelve healthy Wistar male rats were divided into seven groups by random number table, namely a normal group, a sham operation group, a model group, an acupuncture group, a 2 Hz EA group, a 30 Hz EA group, and a 50 Hz EA group, 16 rats in each one. The rats in the normal group were conventionally raised in the laboratory without any treatment. 0.9% NaCl solution was injected into bilateral dentate convolution of hippocampus in rats of the sham operation group. AD model was established by β-amyloid protein1-42 (Aβ1-42) injected into bilateral dentate convolution of hippocampus in the other groups. 15 days after establishment, no treatment was applied in the model and sham operation groups, and EA with corresponding frequencies at "Baihui (GV 20)" and "Shenshu (BL 23)" was used in the three EA groups for 2 sessions, once a day and 7 times as one session. There was 1 day between the two sessions. The same acupoints were adopted in the acupuncture group, without electrical connection. The escape latency, the first spanning platform time, and the number of crossing platform were tested in the Morris water maze immediately after treatment. The expressions of GSK-3β and GAP-43 were examined by immunohistochemistry and Western blot. ①Morris water maze tests showed that the escape latency and the first spanning platform time significantly increased in the model group compared with those in the normal group (both P<0.01), and the number of crossing platform decreased (P<0.01). Compared with the model group, the escape latency and the first spanning platform times decreased in the acupuncture and three EA groups (all P<0.01), and the numbers of crossing platform increased (P<0.01). Compared with the acupuncture and 2 Hz, 30 Hz EA groups, the escape latency decreased in the 50 Hz EA group (P<0.01, P<0.05); the first spanning platform time reduced (all P<0.01); the number of crossing platform increased (P<0.01, P<0.05). ②The expressions of GSK-3β and GAP-43 of the model group increased compared with those of the normal group(both P<0.01). The expressions of GSK-3β in the acupuncture and three EA groups decreased compared with that in the model group (all P<0.01), and the expressions of GAP-43 increased (all P<0.01). The expressions of GSK-3β decreased and GAP-43 increases in the 50 Hz EA group compared with those in the acupuncture group and 2 Hz, 30 Hz groups (all P<0.01). EA may promote synaptic damage rehabilitation by down regulating GSK-3β and up regulating GAP-43 to improve learning and memory ability of AD rats. The effect of 50 Hz EA is better than those of 30 Hz and 2 Hz EA and acupuncture.

The Expression Patterns of c-Fos and c-Jun Induced by Different Frequencies of Electroacupuncture in the Brain

To investigate patterns of c-Fos and c-Jun expression induced by different frequencies of electroacupuncture (EA) in the brain, goats were stimulated by EA of 0, 2, 60, or 100 Hz at a set of “Baihui, Santai, Ergen, and Sanyangluo” points for 30 min. The pain threshold was measured using the potassium iontophoresis method. The levels of c-Fos and c-Jun were determined with Streptavidin-Biotin Complex immunohistochemistry. The results showed that the pain threshold induced by 60 Hz was 82.2% higher (P < 0.01) than that by 0, 2, or 100 Hz (6.5%, 35.2%, or 40.9%). EA induced increased c-Fos and c-Jun expression in most analgesia-related nuclei and areas in the brain. Sixty Hz EA increased more c-Fos or c-Jun expression than 2 Hz or 100 Hz EA in all the measured nuclei and areas except for the nucleus accumbens, the area septalis lateralis, the caudate nucleus, the nucleus amygdala basalis, and the locus coeruleus, in which c-Fos or c-Jun expressions induced by 60 Hz EA did not differ from those by 2 Hz or 100 Hz EA. It was suggested that 60 Hz EA activated more extensive neural circuits in goats, which may contribute to optimal analgesic effects.

Effects of Different Frequencies of Electroacupuncture on Blood Glucose Tolerance Patients

The Journal of Alternative and Complementary MedicineVol. 20, No. 5 Clinical ResearchEffects of Different Frequencies of Electroacupuncture on Blood Glucose Tolerance PatientsHong Meng, Jindong Hao, Hongcai Wang, Jiayong Zhao, Chenlai Zhao, Xu Zhai, Linlin Sun, and Jingyi LiHong MengSearch for more papers by this author, Jindong HaoSearch for more papers by this author, Hongcai WangSearch for more papers by this author, Jiayong ZhaoSearch for more papers by this author, Chenlai ZhaoSearch for more papers by this author, Xu ZhaiSearch for more papers by this author, Linlin SunSearch for more papers by this author, and Jingyi LiSearch for more papers by this authorPublished Online:7 May 2014https://doi.org/10.1089/acm.2014.5113.abstractAboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View article"Effects of Different Frequencies of Electroacupuncture on Blood Glucose Tolerance Patients." The Journal of Alternative and Complementary Medicine, 20(5), p. A44FiguresReferencesRelatedDetails Volume 20Issue 5May 2014 InformationCopyright 2014, Mary Ann Liebert, Inc.To cite this article:Hong Meng, Jindong Hao, Hongcai Wang, Jiayong Zhao, Chenlai Zhao, Xu Zhai, Linlin Sun, and Jingyi Li.Effects of Different Frequencies of Electroacupuncture on Blood Glucose Tolerance Patients.The Journal of Alternative and Complementary Medicine.May 2014.A44-A44.http://doi.org/10.1089/acm.2014.5113.abstractPublished in Volume: 20 Issue 5: May 7, 2014PDF download

An Exploratory Review of the Electroacupuncture Literature: Clinical Applications and Endorphin Mechanisms

Electroacupuncture (EA) is widely used in clinical practice and research, as well as in experimental investigations into the mechanisms of acupuncture. This study explores publication trends in clinical and experimental studies of EA (1975-2011) for pain and non-pain research; EA use for different clinical conditions (1974-2012); and the relation of EA research, including stimulation frequency, to opioid peptide mechanisms. Appropriate PubMed 'all fields' searches were conducted, identified studies were classified using PubMed filters and manually, and data extracted into tables. A total of 2916 clinical studies were located, of which 19% involved EA. Additionally, 3344 animal studies were located, of which 48% involved EA. The publication rate of EA studies per year has risen over time, but the percentage of studies of pain has fallen from 60% to 25%. The conditions most commonly treated with EA are musculoskeletal, neurological, obstetric and gastrointestinal, along with intraoperative and postoperative analgesia. EA studies, particularly with low frequency stimulation, are more likely to support the role of endogenous opioid mechanisms than manual acupuncture studies, and opioid release is more likely in the central nervous system than the circulation. EA is increasingly used in clinical and especially experimental research, particularly for non-pain conditions. Acupuncture does release endogenous opioids, but this probably depends on 'dosage', with the evidence more consistent and convincing for EA than for manual acupuncture. Different frequencies of EA appear to activate different endogenous opioid mechanisms.

Effects of different frequencies of electro-acupuncture at Shuigou (GV 26) on recovery of motor function in rats with focal cerebral ischemic injury

ObjectiveTo investigate the effects of different frequencies of electro-acupuncture at Shuigou (GV 26) on the latent period and wave amplitude of motor evoked potentials (MEPs) in rats with focal cerebral infarction. MethodsFifty healthy male Wistar rats were randomly divided into five groups: controls, model, 2 Hz Shuigou, 50 Hz Shuigou and 100 Hz Shuigou. There were 10 rats in each group. Using a modification of a technique for middle cerebral artery occlusion, focal cerebral ischemic injury was induced in all rats except those in the control group. The rats in the control group received no treatment. After behavioral deficit had been evaluated using the Zausinger 6-point neurological function score, the rats in the Shuigou groups underwent acupuncture and continuous wave stimulation at a frequency of 2 Hz, 50 Hz or 100 Hz (intensity 1 mA) for 10 min twice daily for 3 days. The control and model groups underwent no intervention. Zausinger 6-point neurological function score and MEPs were measured 72 h after the start of treatment. ResultsThe neurological function scores of the three Shuigou groups were significantly higher than those of the model group (P<0.05). There was no significant difference between sides in the latency and amplitude of MEPs in the model group (P>0.05). The latency on the affected side in the model group was significantly longer than that in the control group (P<0.05) and the amplitude on affected side was significantly reduced (P<0.01). After 3 days of electro-acupuncture, the latency on the affected side in the 2 Hz Shuigou group was significantly shortened (P<0.05) and the amplitude was significantly increased (P<0.05) compared with the model group. ConclusionLow frequency electro-acupuncture at Shuigou (GV 26) can promote recovery of motor function after focal cerebral ischemic injury in rats.

Pain relief during oocyte retrieval — exploring the role of different frequencies of electro-acupuncture

Electro-acupuncture has previously proven its analgesic effect in oocyte retrieval for IVF. The aim of the present prospective randomized study was to explore the optimal frequency for analgesia when electro-acupuncture was applied a few minutes prior to oocyte retrieval. A total of 152 patients were prospectively randomized to receive either a combination of high (80 Hz) and low frequency (2 Hz), 3 s each, a so-called mixed frequency, or a fixed frequency of 20 Hz during oocyte retrieval. In addition to electro-acupuncture, both groups had a paracervical block and manual acupuncture. No differences in pain before, during or after oocyte retrieval between the two groups were seen. In the fixed frequency group, however, a higher level of anxiety ( P < 0.05) before oocyte retrieval was seen, and a higher level of nausea after aspiration of one ovary ( P < 0.01) was seen in the mixed frequency group. No differences were seen regarding clinical outcome parameters. Contrary to previous reports on acute and chronic pain, the analgesic effect of the mixed frequency and the fixed frequency was similar when used for short duration electro-acupuncture.

Effect of high or low frequency electroacupuncture on the cellular activity of catecholaminergic neurons in the brain stem.

Although the opioid system plays a pivotal role in the analgesic effect of electroacupuncture (EA), it has been suggested that other peptidergic systems also may be involved in the therapeutic effect of EA. Among several peptides for EA-induced analgesia, catecholamine (CA) is associated with the descending pain inhibitory system. We evaluated whether the different frequencies of EA modified the cellular activity of central CA synthesizing neurons using double labeling immunohistochemistry between Fos-like immunoreactive (FLI) neurons and dopamine-beta-hydroxylase (DBH)/tyrosine hydroxylase (TH)-positive neurons. We observed that different frequencies of EA increased the number of FLI neurons in catecholaminergic neurons, such as the dorsal raphe (DR), hypothalamic arcuate nucleus (Arc), locus coeruleus (LC), A5 noradrenaline cells (A5), and A7 noradrenaline cells (A7). In addition, different frequencies of EA significantly increased the ratio of colocalization between FLI neurons and TH positive neurons in DR, LC and Arc. Only low frequency EA increased the neuronal activity in Arc. The ratio of double labeling between FLI and DBH positive neurons was also elevated at both LC and A5. These data demonstrate that different frequencies of EA increase the cellular activity of central CA synthesizing neurons, suggesting that the CA system plays an important role in EA-induced analgesia.

Different frequencies of electroacupuncture modified the cellular activity of serotonergic neurons in brainstem.

In this study, we evaluated whether different frequencies of electroacupuncture (EA) modified the activities of serotonergic neurons in the dorsal raphe (DR) and raphe magnus (RMg) using double labeling immunohistochemistry for Fos and serotonin. The results demonstrated that both high and low frequency EA increased the colocalization between Fos and serotonin in the DR, not in RMg as compared with anesthesia control. In addition, high frequency EA more potently increased the serotonergic activity in the DR rather than low frequency EA, suggesting that serotonergic pathway from the DR plays an important role in the high frequency EA analgesia.