Effects of Electroacupuncture at Head Points on the Function of Cerebral Motor Areas in Stroke Patients: A PET Study

Acupuncture-Neuroimaging Research Trends over Past Two Decades: A Bibliometric Analysis

OBJECTIVE

To identify topics attracting growing research attention as well as frontier trends of acupuncture-neuroimaging research over the past two decades.

METHODS

This paper reviewed data in the published literature on acupuncture neuroimaging from 2000 to 2020, which was retrieved from the Web of Science database. CiteSpace was used to analyze the publication years, countries, institutions, authors, keywords, co-citation of authors, journals, and references.

RESULTS

A total of 981 publications were included in the final review. The number of publications has increased in the recent 20 years accompanied by some fluctuations. Notably, the most productive country was China, while Harvard University ranked first among institutions in this field. The most productive author was Tian J with the highest number of articles (50), whereas the most co-cited author was Hui KKS (325). Evidence-Based Complementary and Alternative Medicine (92) was the most prolific journal, while Neuroimage was the most co-cited journal (538). An article written by Hui KKS (2005) exhibited the highest co-citation number (112). The keywords "acupuncture" (475) and "electroacupuncture" (0.10) had the highest frequency and centrality, respectively. Functional magnetic resonance imaging (fMRI) ranked first with the highest citation burst (6.76).

CONCLUSION

The most active research topics in the field of acupuncture-neuroimaging over the past two decades included research type, acupoint specificity, neuroimaging methods, brain regions, acupuncture modality, acupoint specificity, diseases and symptoms treated, and research type. Whilst research frontier topics were "nerve regeneration", "functional connectivity", "neural regeneration", "brain network", "fMRI" and "manual acupuncture".

Effect of aging on the cerebral metabolic mechanism of electroacupuncture treatment in rats with traumatic brain injury

Objective

Aging has great influence on the clinical treatment effect of cerebrovascular diseases, and evidence suggests that the effect may be associated with age-related brain plasticity. Electroacupuncture is an effective alternative treatment for traumatic brain injury (TBI). In the present study, we aimed to explore the effect of aging on the cerebral metabolic mechanism of electroacupuncture to provide new evidence for developing age-specific rehabilitation strategies.

Methods

Both aged (18 months) and young (8 weeks) rats with TBI were analyzed. Thirty-two aged rats were randomly divided into four groups: aged model, aged electroacupuncture, aged sham electroacupuncture, and aged control group. Similarly, 32 young rats were also divided into four groups: young model, young electroacupuncture, young sham electroacupuncture, and young control group. Electroacupuncture was applied to "Bai hui" (GV20) and "Qu chi" (LI11) for 8 weeks. CatWalk gait analysis was then performed at 3 days pre- and post-TBI, and at 1, 2, 4, and 8 weeks after intervention to observe motor function recovery. Positron emission computed tomography (PET/CT) was performed at 3 days pre- and post-TBI, and at 2, 4, and 8 weeks after intervention to detect cerebral metabolism.

Results

Gait analysis showed that electroacupuncture improved the forepaw mean intensity in aged rats after 8 weeks of intervention, but after 4 weeks of intervention in young rats. PET/CT revealed increased metabolism in the left (the injured ipsilateral hemisphere) sensorimotor brain areas of aged rats during the electroacupuncture intervention, and increased metabolism in the right (contralateral to injury hemisphere) sensorimotor brain areas of young rats.

Results

This study demonstrated that aged rats required a longer electroacupuncture intervention duration to improve motor function than that of young rats. The influence of aging on the cerebral metabolism of electroacupuncture treatment was mainly focused on a particular hemisphere.

The impact of acupuncture on neuroplasticity after ischemic stroke: a literature review and perspectives

Ischemic stroke is common in the elderly, and is one of the main causes of long-term disability worldwide. After ischemic stroke, spontaneous recovery and functional reconstruction take place. These processes are possible thanks to neuroplasticity, which involves neurogenesis, synaptogenesis, and angiogenesis. However, the repair of ischemic damage is not complete, and neurological deficits develop eventually. The WHO recommends acupuncture as an alternative and complementary method for the treatment of stroke. Moreover, clinical and experimental evidence has documented the potential of acupuncture to ameliorate ischemic stroke-induced neurological deficits, particularly sequelae such as dyskinesia, spasticity, cognitive impairment, and dysphagia. These effects are related to the ability of acupuncture to promote spontaneous neuroplasticity after ischemic stroke. Specifically, acupuncture can stimulate neurogenesis, activate axonal regeneration and sprouting, and improve the structure and function of synapses. These processes modify the neural network and function of the damaged brain area, producing the improvement of various skills and adaptability. Astrocytes and microglia may be involved in the regulation of neuroplasticity by acupuncture, such as by the production and release of a variety of neurotrophic factors, including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF). Moreover, the evidence presented indicates that acupuncture promotes neuroplasticity by modulating the functional reconstruction of the whole brain after ischemia. Therefore, the promotion of neuroplasticity is expected to become a new target for acupuncture in the treatment of neurological deficits after ischemic stroke, and research into the mechanisms responsible for these actions will be of significant clinical value.

Mechanisms of Acupuncture in the Regulation of Oxidative Stress in Treating Ischemic Stroke

Ischemic stroke is the major type of cerebrovascular disease usually resulting in death or disability among the aging population globally. Oxidative stress has been closely linked with ischemic stroke. Disequilibrium between excessive production of reactive oxygen species (ROS) and inherent antioxidant capacity leads to subsequent oxidative damage in the pathological progression of ischemic brain injury. Acupuncture has been applied widely in treating cerebrovascular diseases from time immemorial in China. This review mainly lays stress on the evidence to illuminate the possible mechanisms of acupuncture therapy in treating ischemic stroke through regulating oxidative stress. We found that by regulating a battery of molecular signaling pathways involved in redox modulation, acupuncture not only activates the inherent antioxidant enzyme system but also inhibits the excessive generation of ROS. Acupuncture therapy possesses the potential in alleviating oxidative stress caused by cerebral ischemia, which may be linked with the neuroprotective effect of acupuncture.

The Therapeutic Effect of Electroacupuncture Therapy for Ischemic Stroke

Electroacupuncture (EA) stimulation is a supplementary therapy and commonly applied in treatment of ischemic stroke in clinic. Stroke is an important cause of long-term disability in individuals in both developing and developed countries. In our review, we show the application of EA stimulation for apoplectic pain, limbs spasticity, blood flow interruption, depression, swallowing dysfunction, aphasia, urinary incontinence, cognition and memory impairment, and constipation following stroke in patients and the related mechanisms in animals. The effectiveness of EA involves with acupoints, intensity, intervals, and duration of intervention for treatment of stroke. The combination of EA and common rehabilitation treatment may exert better effect compared with EA alone. In summary, EA might provide a potential treatment strategy for treating apoplectic patients in clinic.

Disease Stage-Associated Alterations in Learning and Memory through the Electroacupuncture Modulation of the Cortical Microglial M1/M2 Polarization in Mice with Alzheimer's Disease

Microglia are the primary cells that exert immune function in the central nervous system, and accumulating evidence suggests that microglia act as critical players in the initiation of neurodegenerative disorders, such as Alzheimer's disease (AD). Microglia seemingly demonstrate two contradictory phenotypes in response to different microenvironmental cues, the M1 phenotype and the M2 phenotype, which are detrimental and beneficial to pathogenesis, respectively. Inhibiting the M1 phenotype with simultaneous promoting the M2 phenotype has been suggested as a potential therapeutic approach for cure AD. In this study, we demonstrated that electroacupuncture at the Shenting and Baihui acupoints for 16 weeks could improve learning and memory in the Morris water maze test and reduce amyloid β-protein in the parietal association cortex and entorhinal cortex in mice with mild and moderate AD. Besides, electroacupuncture at the Shenting and Baihui acupoints not only suppressed M1 marker (iNOS/IL-1β) expression but also increased the M2 marker (CD206/Arg1) expression in those regions. We propose that electroacupuncture at the Shenting and Baihui acupoints could regulate microglial polarization and decrease Aβ plaques to improve learning and memory in mild AD mice.

Electroacupuncture ameliorates cerebral ischemia/reperfusion injury by suppressing autophagy via the SIRT1-FOXO1 signaling pathway

Cerebral ischemia/reperfusion (CIR) injury occurs when blood flow is restored in the brain, causing secondary damage to the ischemic tissues. Previous studies have shown that electroacupuncture (EA) treatment contributes to brain protection against CIR injury through modulating autophagy. Studies indicated that SIRT1-FOXO1 plays a crucial role in regulating autophagy. Here we investigated the mechanisms underlying the neuroprotective effect of EA and its role in modulating autophagy via the SIRT1-FOXO1 signaling pathway in rats with CIR injury. EA pretreatment at "Baihui", "Quchi" and "Zusanli" acupoints (2/15Hz, 1mA, 30 min/day) was performed for 5 days before the rats were subjected to middle cerebral artery occlusion, and the results indicated that EA pretreatment substantially reduced the Longa score and infarct volume, increased the dendritic spine density and lessened autophagosomes in the peri-ischemic cortex of rats. Additionally, EA pretreatment also reduced the ratio of LC3-II/LC3-I, the levels of Ac-FOXO1 and Atg7, and the interaction of Ac-FOXO1 and Atg7, but increased the levels of p62, SIRT1, and FOXO1. The above effects were abrogated by the SIRT1 inhibitor EX527. Thus, we presume that EA pretreatment elicits a neuroprotective effect against CIR injury, potentially by suppressing autophagy via activating the SIRT1-FOXO1 signaling pathway.

The Status of the Acupuncture Mechanism Study Based on PET/PET-CT Technique: Design and Quality Control

PET/PET-CT is an important technique to investigate the central mechanism of acupuncture in vivo. This article collected original research papers with keywords of "Acupuncture," "PET," "PET/CT," and "Positron emission tomography" in PubMed and CNKI databases from January 2003 to December 2018. As a result, a total of 43 articles were included. Based on the literature analyses, we found that (1) reasonable arrangement of the operation process and the choice of appropriate acupuncture intervention time is conducive to a better interpretation of acupuncture-PET/PET-CT mechanism and (2) the selection of participants, sample size, acupuncture intervention, and experimental conditions would affect study results. Therefore, effective quality control is an important way to ensure the repeatability of research results.

A cross-sectional survey of clinical factors that influence the use of traditional Korean medicine among children with cerebral palsy

Background

Traditional Korean medicine (TKM) is widely used to treat children with cerebral palsy (CP) in Korea; however, studies investigating factors that influence the use of TKM are scarce. Thus, we investigated the clinical factors that might influence the use of TKM.

Methods

A population-based, cross-sectional, multicenter survey was performed from August 2014 to May 2016. The history of TKM use, type and severity of CP, current treatment characteristics, presence of accompanying disabilities or other health problems not directly related to CP, and monthly cost for the treatment of CP were surveyed.

Results

In total, 182 children were recruited, and 78 children (42.9%) had used TKM. Among these 78 children, 50 (64.1% of the TKM-use group) had used both acupuncture and herbal medication, 15 (19.2%) had used acupuncture only, and 13 (16.7%) had used herbal medication only. Children with non-typical CP, accompanying disabilities and general health problems tended to use TKM. The monthly cost of treatment for CP was significantly higher in the TKM-use group than that in the no-TKM-use group, suggesting that economically disadvantaged children may have difficulty in accessing TKM. Dietary supplements, conventional pharmacological treatments, and rehabilitation therapies did not affect TKM use.

Conclusion

Children with non-typical symptoms or those with poor overall health status are likely to use TKM. Additionally, TKM use leads to increased treatment costs. Studies investigating the motivation for starting or ceasing TKM therapy, socioeconomic factors and the attitude of parents towards complementary and alternative medicine should be performed.

Regional Homogeneity and Multivariate Pattern Analysis of Cervical Spondylosis Neck Pain and the Modulation Effect of Treatment

Objects: We investigated brain functional alteration in patients with chronic cervical spondylosis neck pain (CSNP) compared to healthy controls (HCs) and the effect of intervention. Methods: 104 CSNP patients and 96 matched HCs were recruited. Patients received 4 weeks of treatment. Resting-state fMRI and Northwick Park Neck Pain Questionnaire (NPQ) were collected before and after treatment. Resting state regional homogeneity (rs-ReHo) and multivariate pattern analysis (MVPA) were applied to (1) investigate rs-ReHo differences between CSNP patients and controls and the effect of longitudinal treatment and (2) classify CSNP patients from HCs and predict clinical outcomes before treatment using MVPA. Results: We found that (1) CSNP patients showed decreased rs-ReHo in the left sensorimotor cortex and right temporo-parietal junction (rTPJ), and rs-ReHo at the rTPJ significantly increased after treatment; (2) rs-ReHo at rTPJ was associated with NPQ at baseline, and pre- and post-treatment rs-ReHo changes at rTPJ were associated with NPQ changes in CSNP patients; and (3) MVPA could discriminate CSNP patients from HCs with 72% accuracy and predict clinical outcomes with a mean absolute error of 19.6%. Conclusion: CSNP patients are associated with dysfunction of the rTPJ and sensorimotor area. Significance: rTPJ plays on important role in the pathophysiology and development of CSNP.

Baihui (DU20)-penetrating-Qubin (GB7) acupuncture inhibits apoptosis in the perihemorrhagic penumbra

Baihui (DU20)-penetrating-Qubin (GB7) acupuncture can inhibit inflammatory reactions and activate signaling pathways related to proliferation after intracerebral hemorrhage. However, there is no research showing the relationship between this treatment and cell apoptosis. Rat models of intracerebral hemorrhage were established by injecting 60 μL of autologous blood into the right side of the caudate-putamen. Six hours later, the needle traveled subcutaneously from the Baihui acupoint to Qubin acupoint. The needle was alternately rotated (180 ± 10 turns/min) manually along clockwise and counter-clockwise directions. Stimulation lasted for 7 days, and was performed three times each for 6 minutes with 6-minute intervals between stimulations. Rats intraperitoneally receiving Sonic hedgehog pathway activator, purmorphamine (1 mg/kg per day), served as positive controls. Motor and sensory function were assessed using the Ludmila Belayev test. Extent of pathological changes were measured in the perihemorrhagic penumbra using hematoxylin-eosin staining. Apoptosis was examined by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling assay. Expression of smoothened (Smo) and glioma-associated homolog 1 (Gli1) was determined by western blot assay. Our results showed that Baihui-penetrating-Qubin acupuncture promoted recovery of motor and sensory function, reduced the apoptotic cell percentage in the perihemorrhagic penumbra, and up-regulated Smo and Gli1 expression. We conclude that Baihui-penetrating-Qubin acupuncture can mitigate hemorrhage and promote functional recovery of the brain in a rat model of intracerebral hemorrhage, possibly by activating the Sonic hedgehog pathway.

Acupuncture and neuroregeneration in ischemic stroke

Acupuncture is potentially beneficial for post-stroke rehabilitation and is considered a promising preventive strategy for stroke. Electroacupuncture pretreatment or treatment after ischemic stroke by using appropriate electroacupuncture parameters generates neuroprotective and neuroregenerative effects that increase cerebral blood flow, regulate oxidative stress, attenuate glutamate excitotoxicity, maintain blood-brain barrier integrity, inhibit apoptosis, increase growth factor production, and induce cerebral ischemic tolerance.

Electroacupuncture promotes axonal regeneration in rats with focal cerebral ischemia through the downregulation of Nogo-A/NgR/RhoA/ROCK signaling

The purpose of the present study was to evaluate the effect of electroacupuncture (EA) on the axonal regeneration environment following cerebral ischemia injury and to investigate whether it was associated with Nogo-A/Nogo receptor (NgR)/RhoA/Rho-associated protein kinase (ROCK) signaling. Using a rat model of focal cerebral ischemia, the effects of EA at the Quchi (LI11) and Zusanli (ST36) acupoints on axonal growth inhibitory protein and axonal growth factors were assessed and the underlying molecular mechanisms were investigated. It was found that EA at the Quchi and Zusanli acupoints significantly improved neurological deficit scores following ischemia (P<0.05), and reduced the cerebral infarct volume. Moreover, it was demonstrated that crucial signaling molecules in the Nogo-A signaling pathway were regulated by EA. These results suggest that EA provides a less inhibitory environment for axonal regeneration following cerebral ischemia through inhibition of Nogo-A/NgR/RhoA/ROCK signaling.

Spatiotemporal changes of optical signals in the somatosensory cortex of neuropathic rats after electroacupuncture stimulation

Background

Peripheral nerve injury causes physiological changes in primary afferent neurons. Neuropathic pain associated with peripheral nerve injuries may reflect changes in the excitability of the nervous system, including the spinothalamic tract. Current alternative medical research indicates that acupuncture stimulation has analgesic effects in various pain symptoms. However, activation changes in the somatosensory cortex of the brain by acupuncture stimulation remain poorly understood. The present study was conducted to monitor the changes in cortical excitability, using optical imaging with voltage-sensitive dye (VSD) in neuropathic rats after electroacupuncture (EA) stimulation.

Methods

Male Sprague–Dawley rats were divided into three groups: control (intact), sham injury, and neuropathic pain rats. Under pentobarbital anesthesia, rats were subjected to nerve injury with tight ligation and incision of the tibial and sural nerves in the left hind paw. For optical imaging, the rats were re-anesthetized with urethane, and followed by craniotomy. The exposed primary somatosensory cortex (S1) was stained with VSD for one hour. Optical signals were recorded from the S1 cortex, before and after EA stimulation on Zusanli (ST36) and Yinlingquan (SP9).

Results

After peripheral stimulation, control and sham injury rats did not show significant signal changes in the S1 cortex. However, inflamed and amplified neural activities were observed in the S1 cortex of nerve-injured rats. Furthermore, the optical signals and region of activation in the S1 cortex were reduced substantially after EA stimulation, and recovered in a time-dependent manner. The peak fluorescence intensity was significantly reduced until 90 min after EA stimulation (Pre-EA: 0.25 ± 0.04 and Post-EA 0 min: 0.01 ± 0.01), and maximum activated area was also significantly attenuated until 60 min after EA stimulation (Pre-EA: 37.2 ± 1.79 and Post-EA 0 min: 0.01 ± 0.10).

Conclusion

Our results indicate that EA stimulation has inhibitory effects on excitatory neuronal signaling in the S1 cortex, caused by noxious stimulation in neuropathic pain. These findings suggest that EA stimulation warrants further study as a potential adjuvant modulation of neuropathic pain.

White matter injury in ischemic stroke

Stroke is one of the major causes of disability and mortality worldwide. It is well known that ischemic stroke can cause gray matter injury. However, stroke also elicits profound white matter injury, a risk factor for higher stroke incidence and poor neurological outcomes. The majority of damage caused by stroke is located in subcortical regions and, remarkably, white matter occupies nearly half of the average infarct volume. Indeed, white matter is exquisitely vulnerable to ischemia and is often injured more severely than gray matter. Clinical symptoms related to white matter injury include cognitive dysfunction, emotional disorders, sensorimotor impairments, as well as urinary incontinence and pain, all of which are closely associated with destruction and remodeling of white matter connectivity. White matter injury can be noninvasively detected by MRI, which provides a three-dimensional assessment of its morphology, metabolism, and function. There is an urgent need for novel white matter therapies, as currently available strategies are limited to preclinical animal studies. Optimal protection against ischemic stroke will need to encompass the fortification of both gray and white matter. In this review, we discuss white matter injury after ischemic stroke, focusing on clinical features and tools, such as imaging, manifestation, and potential treatments. We also briefly discuss the pathophysiology of WMI and future research directions.

The Status of the Quality Control in Acupuncture-Neuroimaging Studies

Using neuroimaging techniques to explore the central mechanism of acupuncture gains increasing attention, but the quality control of acupuncture-neuroimaging study remains to be improved. We searched the PubMed Database during 1995 to 2014. The original English articles with neuroimaging scan performed on human beings were included. The data involved quality control including the author, sample size, characteristics of the participant, neuroimaging technology, and acupuncture intervention were extracted and analyzed. The rigorous inclusion and exclusion criteria are important guaranty for the participants' homogeneity. The standard operation process of acupuncture and the stricter requirement for acupuncturist play significant role in quality control. More attention should be paid to the quality control in future studies to improve the reproducibility and reliability of the acupuncture-neuroimaging studies.

The change in cerebral glucose metabolism after electroacupuncture: a possible marker to predict the therapeutic effect of deep brain stimulation for refractory anorexia nervosa

Some reports have demonstrated that deep brain stimulation (DBS) is a promising treatment for patients who suffer from intractable anorexia nervosa. However, the nature of DBS may not be viewed as a standard clinical treatment option for anorexia nervosa because of the unpredictable outcome before DBS. Just like DBS in the brain, electroacupuncture at acupoints is also efficient in treating refractory anorexia nervosa. Some neuroimaging studies using functional magnetic resonance imaging, single-photon emission computed tomography (SPECT), and positron emission tomography (PET) had revealed that both DBS and electroacupuncture at acupoints with electrical stimulation are related to the changes in cerebral glucose metabolism. Therefore, we hypothesize that the changes in cerebral glucose metabolism after electroacupuncture might be useful to predict the therapeutic effect of deep brain stimulation for refractory anorexia nervosa.

Electroacupuncture ameliorates learning and memory in rats with cerebral ischemia-reperfusion injury by inhibiting oxidative stress and promoting p-CREB expression in the hippocampus

The present study aimed to investigate the mechanisms by which electroacupuncture (EA) ameliorates learning and memory in rats with cerebral ischemic‑reperfusion (I/R) injury. Focal cerebral ischemia was induced in adult male Sprague‑Dawley (SD) rats by transient middle cerebral artery occlusion (MCAO). Following MCAO surgery, the rats received EA at the Shenting (DU24) and Baihui (DU20) acupoints. The results of the present study demonstrated that treatment with EA significantly ameliorated neurological deficits and reduced cerebral infarct volume (P<0.05). In addition, EA improved the learning and memory ability of the rats, and markedly activated the cyclic adenosine monophosphate (cAMP) response element‑binding protein (CREB) signaling pathway, resulting in the inhibition of cerebral cell apoptosis in the ischemic penumbra. Furthermore, EA increased the activity of superoxide dismutase and glutathione peroxidase, the protein expression levels of phosphorylated‑CREB and B‑cell lymphoma 2 (Bcl‑2), and the mRNA expression levels of Bcl‑2. Conversely, EA decreased the levels of malondialdehyde and inhibited the expression levels of Bcl2‑associated X protein. The results of the present study suggest that treatment with EA may result in the amelioration of learning and memory ability in rats with cerebral I/R injury.

Neuroprotective effects of electroacupuncture on hypoxic-ischemic encephalopathy in newborn rats are associated with increased expression of GDNF-RET and protein kinase B

OBJECTIVE

To explore the neuroprotective effects of electroacupuncture (EA) on hypoxic-ischemic encephalopathy (HIE) and to further investigate the role of glial cell line-derived neurotrophic factor (GDNF) family receptor member RET (rearranged during transfection) and its key downstream phosphatidylinositol 3 kinase (PI-3K)/protein kinase B (Akt) pathway in the process.

METHODS

A total of 220 seven-day-old SD rats (of either sex, from 22 broods) were randomly divided into two groups, one (30 rats) for sham-surgery group and the other (190 rats) for HIE model group. The HIE model was established using the left common carotid artery ligation method in combination with hypoxic treatment. The successfully established rats were randomly divided into five groups, including control model group, EA group, sham-EA group, antagonist group and antagonist plus electroacupuncture group, with 35 rats in each group. Baihui (GV 20), Dazhui (GV 14), Quchi (LI 11) and Yongquan (KI 1) acupoints were chosen for acupuncture. EA was performed at Baihui and Quchi for 10 min once a day for continuous 1, 3, 7 and 21 days, respectively. The rats were then killed after the operation and injured cerebral cortex was taken for the measurement of neurologic damage by hematoxylin-eosin (HE) staining and the degenerative changes of cortical ultrastructure by transmission electron microscopy. RET mRNA level and Akt protein level were detected by real-time reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis, respectively.

RESULTS

EA could ameliorate neurologic damage of the first somatic sensory area (S1Tr) and alleviate the degenerative changes of ultrastructure of cortical neurons in rats subjected to HIE. And the longer acupuncture treatment lasted, the better its therapeutic effect would be. This was accompanied by gradually increased expression of GDNF family receptor RET at the mRNA level and its downstream signaling Akt at the protein level in the ischemic cortex.

CONCLUSION

EA has neuroprotective effects on HIE and could be a potential therapeutic strategy for HIE in the neonate. Activation of RET/Akt signaling pathway might be involved in this process.

Acupuncture stimulation improves scopolamine-induced cognitive impairment via activation of cholinergic system and regulation of BDNF and CREB expressions in rats

Background

Acupuncture is an alternative therapy that is widely used to treat various neurodegenerative diseases and effectively improve cognitive and memory impairment. The aim of this study was to examine whether acupuncture stimulation at the Baihui (GV20) acupoint improves memory defects caused by scopolamine (SCO) administration in rats. We also investigated the effects of acupuncture stimulation at GV20 on the cholinergic system as well as the expression of brain-derived neurotrophic factor (BDNF) and cAMP-response element-binding protein (CREB) in the hippocampus.

Methods

SCO (2 mg/kg, i.p.) was administered to male rats once daily for 14 days. Acupuncture stimulation at GV20 was performed for 5 min before SCO injection. After inducing cognitive impairment via SCO administration, we conducted a passive avoidance test (PAT) and the Morris water maze (MWM) test to assess behavior.

Results

Acupuncture stimulation at GV20 improved memory impairment as measured by the PAT and reduced the escape latency for finding the platform in the MWM test. Acupuncture stimulation at GV20 significantly alleviated memory-associated decreases in the levels of choline acetyltransferase (ChAT), BDNF and CREB proteins in the hippocampus. Additionally, acupuncture stimulation at GV20 significantly restored the expression of choline transporter 1 (CHT1), vesicular acetylcholine transporter (VAChT), BDNF and CREB mRNA in the hippocampus. These results demonstrate that acupuncture stimulation at GV20 exerts significant neuroprotective effects against SCO-induced neuronal impairment and memory dysfunction in rats.

Conclusions

These findings suggest that acupuncture stimulation at GV20 might be useful in various neurodegenerative diseases to improve cognitive functioning via stimulating cholinergic enzyme activities and regulating BDNF and CREB expression in the brain.

A systematic review and meta-analysis of Baihui (GV20)-based scalp acupuncture in experimental ischemic stroke

Acupuncture for stroke has been used in China for over 2,000 years and nowadays is increasingly practiced elsewhere in the world. However, previous studies had conflicting findings on the results of acupuncture. Here, we conducted a systematic review and meta-analysis to assess the current evidence for the effect of Baihui (GV20)-based scalp acupuncture in animal models of focal cerebral ischemia. Six databases from the inception of each database up to June 2013 were electronically searched. Primary outcomes were infarct size and neurobehavioral outcome. Ultimately, 54 studies involving 1816 animals were identified describing procedures. Meta-analysis results showed that twelve studies reported significant effects of Baihui (GV20)-based scalp acupuncture for improving infarct volume compared with middle cerebral artery occlusion group (P < 0.01), and thirty-two studies reported significant effects of Baihui (GV20)-based scalp acupuncture for improving the neurological function score when compared with the control group (P < 0.01). In conclusion, Baihui (GV20)-based scalp acupuncture could improve infarct volume and neurological function score and exert potential neuroprotective role in experimental ischemic stroke.

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

Although systematic studies have demonstrated that acupuncture or electroacupuncture (EA) analgesia is based on their accelerating endogenous opioid release to activate opioid receptors and that EA of different frequencies is mediated by different opioid receptors in specific areas of the central nervous system, there is little direct, real-time evidence to confirm this in vivo. The present study was designed to investigate the effects of transcutaneous electrical acupoint stimulation (TEAS), an analogue of EA, at low and high frequencies on μ-opioid receptor (MOR) availability in the brain of rhesus monkeys. Monkeys underwent 95-min positron emission tomography (PET) with (11) C-carfentanil three times randomly while receiving 0, 2, or 100 Hz TEAS, respectively. Each TEAS was administered in the middle 30 min during the 95-min PET scan, and each session of PET and TEAS was separated by at least 2 weeks. The results revealed that 2 Hz but not 100 Hz TEAS evoked a significant increase in MOR binding potential in the anterior cingulate cortex, the caudate nucleus, the putamen, the temporal lobe, the somatosensory cortex, and the amygdala compared with 0 Hz TEAS. The effect remained after the end of TEAS in the anterior cingulate cortex and the temporal lobe. The selective increase in MOR availability in multiple brain regions related to pain and sensory processes may play a role in mediating low-frequency TEAS efficacy.

Interaction of acupuncture and electroacupuncture on the pharmacokinetics of aspirin and the effect of brain blood flow in rats

Acupuncture and electroacupuncture have been used to improve the brain and motor functions of poststroke patients, and aspirin is used for the prevention of stroke recurrence. Our hypothesis is that acupuncture and electroacupuncture treatments may interact with aspirin in terms of pharmacokinetics via affecting the brain blood flow. The aim of this study is to investigate the potential interactions of acupuncture and electroacupuncture on the pharmacokinetics of aspirin. The effects of acupuncture treatments on brain blood flow were measured by the laser Doppler blood flow imager. The parallel pharmacokinetic study design included three groups: control, acupuncture, and electroacupuncture groups. Two acupoints, namely, Quchi (LI 11) and Zusanli (ST 36), were needled and stimulated electronically in anaesthetized rats. The concentrations of aspirin and its metabolite, salicylic acid were determined by microdialysis and HPLC analysis after aspirin administration (30 mg/kg, i.v.). The brain blood flow responded to electroacupuncture treatments, but the pharmacokinetic parameters of aspirin and salicylic acid in blood and brain were not significantly changed by acupuncture and electroacupuncture treatments. This study may, in part, offer some evidence to support the contention that there is no significant interaction for the combination of aspirin with acupuncture or electroacupuncture.

Electro-acupuncture at points of Zusanli and Quchi exerts anti-apoptotic effect through the modulation of PI3K/Akt signaling pathway

We evaluated the neuroprotective effect of electro-acupuncture (EA) on cerebral ischemia-reperfusion (IR) injury and deeply investigated the relationship between this neuroprotective effect and PI3K/Akt pathway. Rats underwent focal cerebral IR injured by suture method and received the in vivo therapeutic efficacy of EA at points of Zusanli(ST36) and Quchi(LI11) after the operation. We found that the EA treatment significantly (p<0.05) improved neurological deficit and cerebral infarction. Furthermore, EA profoundly activated PI3K/Akt signaling resulted in the inhibition of cerebral cell apoptosis in the ischemic penumbra. Simultaneously EA increased the expression of PI3K, p-Akt, p-Bad and Bcl-2 at the protein level and the expression of Bcl-2 at the mRNA level. On the contrary, EA inhibited the Bax and cleaved Caspase-3-positive expression. The selective PI3K inhibitor LY294002 compromised EA-induced neuroprotective effects and reduced the elevation of p-Akt, p-Bad and Bcl-2 levels. Our data suggested that the PI3K/Akt pathway played a critical role in mediating the neuroprotective effects of EA treatment at points of Zusanli and Quchi after the ischemic stroke.

Electroacupuncture Ameliorates Learning and Memory via Activation of the CREB Signaling Pathway in the Hippocampus to Attenuate Apoptosis after Cerebral Hypoperfusion

Studies have shown that electroacupuncture (EA) ameliorates learning and memory after ischemic injury. However, there have been few studies elucidating the mechanisms of EA on learning and memory in cerebral hypoperfusion. In this study, we explored the cAMP response element-binding protein (CREB) signaling pathway-mediated antiapoptotic action involved in EA-induced improvement of learning and memory. EA at GV20 and GV14 acupoints was applied in cerebral hypoperfusion rats. A Morris water maze task was performed, and the immunoreactivities of pCREB, Bcl-2, and Bax in the hippocampal CA1 area were evaluated by the Western blotting technique. Our findings indicated that (1) EA ameliorated spatial learning and memory impairment in cerebral hypoperfusion rats; (2) EA increased the immunoreactivities of pCREB and Bcl-2 and decreased the immunoreactivity of Bax; (3) intracerebroventricular administration of H89 (the inhibitor of protein kinase A) blocked EA-induced, pCREB-mediated antiapoptotic action and improved learning and memory. These results suggest that EA can ameliorate learning and memory via activation of the CREB signaling pathway in the hippocampus to attenuate apoptosis after cerebral hypoperfusion.

Effects of electroacupuncture on apoptotic pathways in a rat model of focal cerebral ischemia

In this study, we investigated the molecular mechanisms underlying the anti-apoptotic properties of electroacupuncture (EA) in a rat model of middle cerebral artery occlusion (MCAO). Treatment with 2 Hz EA (1 mA) resulted in a markedly reduced infarct area after stroke, particularly in the middle region of the brain. Treatment with EA resulted in a significant decrease in the number of apoptotic cells identified by Hoechst 33342 and TUNEL staining. According to the results of the analysis for proteins involved in apoptosis, treatment with EA resulted in a significantly reduced expression of death receptor (DR)5. Among the members of the Bcl‑2 family, a higher expression of anti-apoptotic Bcl‑2 and Bcl‑xL was observed in the rats treated with EA, compared with the untreated rats with MCAO. As regards the expression of the inhibitor of apoptosis protein (IAP) family, a higher expression of anti-apoptotic cIAP‑1 and ‑2 was also detected in the cortex of the EA‑treated rats. Using western blot analysis, we observed that activated caspase‑3 was only significantly arrested by EA treatment in the rats with MCAO; however, according to the results of the caspase assay, the activities of caspase‑3, ‑8 and ‑9 were markedly inhibited by EA treatment. These results suggest that treatment with EA exerts anti‑apoptotic effects in cerebral ischemia in a rat model of MCAO and that these effects are associated with the inhibition of the DR and mitochondrial apoptotic pathways.

Acupuncture therapy for stroke patients

Acupuncture is one of the most important parts of Traditional Chinese Medicine, has been used for more than 3000 years as prevention and treatment for various diseases in China as well as in adjacent regions, and is widely accepted in western countries in recent years. More and more clinical trials revealed that acupuncture shows positive effect in stroke, not only as a complementary and alternative medicine for poststroke rehabilitation but also as a preventive strategy which could induce cerebral ischemic tolerance, especially when combined with modern electrotherapy. Acupuncture has some unique characteristics, which include acupoint specificity and parameter-dependent effect. It also involves complicated mechanism to exert the beneficial effect on stroke. Series of clinical trials have shown that acupuncture primarily regulates the release of neurochemicals, hemorheology, cerebral microcirculation, metabolism, neuronal activity, and the function of specific brain region. Animal studies showed that the effects of acupuncture therapy on stroke were possibly via inhibition of postischemic inflammatory reaction, stimulation of neurogenesis and angiogenesis, and influence on neural plasticity. Mechanisms for its preconditioning effect include activity enhancement of antioxidant, regulation of the endocannabinoid system, and inhibition of apoptosis. Although being controversial, acupuncture is a promising preventive and treatment strategy for stroke, but further high-quality clinical trials would be needed to provide more confirmative evidence.

Use of acupuncture to treat cerebral infarction in the last 10 years: A Scopus-based literature analysis

OBJECTIVE:

To identify global research trends in the use of acupuncture to treat cerebral infarction.

DATA RETRIEVAL:

We performed a bibliometric analysis of studies on the use of acupuncture to treat cerebral infarction published during 2002–2011, retrieved from Scopus, using the key words of acupuncture and cerebral infarction or ischemic stroke.

SELECTION CRITERIA:

Inclusion criteria: peer-reviewed articles on the use of acupuncture to treat cerebral infarction indexed in Scopus and published between 2002 and 2011; types of publications were original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items. Exclusion criteria: articles that required manual searching or telephone access; documents that were not published in the public domain; and corrected papers.

MAIN OUTCOME MEASURES:

(a) Annual publication output; (b) language of publication; (c) type of publication; (d) key words of publication; (e) publication by research field; (f) publication by journal; (g) publication by country and institution; (h) publication by author; (i) most-cited papers between 2002 and 2006; and (j) most-cited papers between 2007 and 2011.

RESULTS:

A total of 160 publications on the use of acupuncture to treat cerebral infarction from 2002–2011 were retrieved from Scopus. The number of publications increased gradually over the 10-year study period; most were written in Chinese or English. Articles and reviews constituted the major types. The most frequent key word used was acupuncture. The most prolific journals in this area were Zhongguo Zhen Jiu and the Chinese Journal of Clinical Rehabilitation. Of the 160 publications retrieved, half came from Chinese authors and institutions. Tianjin University of Traditional Chinese Medicine was the most prolific research institute. Two papers were cited 30 times; they were published in 2002 and 2009, respectively.

CONCLUSION:

In the field of neuroscience, there is little literature on acupuncture for cerebral infarction. The most-cited papers were cited 30 times in the past 3 years. We believe that, with advances in the study of mechanisms in neurobiology, research on acupuncture will also advance and will become the concern of more scholars.