PC6 Acupoint Research Articles

Activation of Cerebral Cortex Evoked by Magnetic Stimulation at Acupuncture Point

Magnetic stimulation is a non-invasive and almost painless technique and has been used to modulate nerve activities, treat disorders and maintain health, just like acupuncture. Acupuncture point (acupoint) is a specific point in human body with high sensitivity to acupuncture treatment. In this paper, magnetic stimulation was used to stimulate Neiguan (PC6) acupoint. 64-channel EEG signals in three stages (before, during and after magnetic stimulation) were recorded to determine whether magnetic stimulation at PC6 acupoint might modulate ongoing EEG or not and whether specific cerebral cortex areas would be activated. C0 complexity of EEG signals was analyzed. The statistical analysis results showed that the parietal lobe of cerebral cortex covered by P1, PZ and P2 electrodes was activated during magnetic stimulation at PC6 acupoint, temporal lobe and parietal-occipital lobe covered by T7, P5, PO7, PO5 electrodes were activated after magnetic stimulation. It suggested that magnetic stimulation at PC6 acupoint would activate specific cerebral cortex areas.

Effects of Electroacupuncture Pretreatment on Inflammatory Response and Acute Kidney Injury in Endotoxaemic Rats

This study investigated the effect of electroacupuncture pretreatment on the lipopolysaccharide (LPS)-induced inflammatory response and on acute kidney injury in adult male pathogen-free Wistar rats. Rats received electroacupuncture at the Zusanli (ST36) and Neiguan (PC6) acupoints, or electrical stimulation at sham points, for 30 min before stimulation with either 5 mg/kg LPS intravenously or normal saline. Plasma cytokines, plasma nitrite, renal inducible nitric oxide synthase (iNOS) and nuclear factor κB (NF-κB) activity were assessed 240 min after LPS or normal saline injection. Blood urea nitrogen (BUN), creatinine (Cr) and histopathological score for renal tubular damage were also measured. Electroacupuncture pretreatment significantly decreased LPS-induced plasma tumour necrosis factor-α and interleukin (IL)-1β, increased plasma IL-10, and decreased plasma nitrite, renal iNOS and NF-κB activity. It also significantly decreased LPS-induced BUN, Cr and the renal histopathological score. These findings suggest that electroacupuncture pretreatment at the ST36 and PC6 acupoints attenuated the LPS-induced inflammatory response and mitigated acute kidney injury.

S2077 Gastric Electrical Response to Different Stimulation Parameters via Intraoperative Egg Recordings

Background and Aims: Acupuncture or electroacupuncture (EA) has been applied for treating chemotherapy-induced emesis with limited success. Two major problems with EA include infrequent application of EA and suboptimal stimulation parameters. The aims of this study were to investigate the feasibility of EA using chronically implanted electrodes and the effects of EA with different parameters on cisplatin-induced emesis in rats assessed by pica (intake of kaolin) that has been validated as a surrogate of emesis in rats. Materials and Methods: Under anesthesia, 19 SD rats were chronically implanted with a pair of electrodes at bilateral acupoint PC6 as follows: A 3mm tip of the exposed wire (serving as an electrode) was inserted into the acupoint and the connecting wire was firstly fixed in the muscle layer around the acupoint, then tunneled subcutaneously to the back of the neck and finally exited and protected for EA. After recovery and appropriate acclimation, the rats were treated using a 3×3 Latin Square cross-over design in which each rat received a sequence of 3 treatments in one of 3 assigned orders. The treatments included the following: EA1: 20Hz, 0.6ms, 2mA and continuous stimulation; EA2: 10Hz, 1.2ms, 2mA and continuous stimulation; Control: no stimulation. During each treatment, cisplatin 6mg/kg was injected intraperitoneally at 3PM during the first day and the rats received with one of the three treatments while staying at a rat restrainer for 3 hrs from 6pm-9m daily for 2 days. During the other periods, the rats were housed in their individual cages. There was an interval of 2 weeks between the two consecutive treatments. Results: 1) The implanted electrodes remained secured at the acupoints without infections. 2) Cisplatin induced substantial kaolin intake as well as reduced food intake and body weight; Treatment with EA1 significantly reduced kaolin intake on the first and second day after cisplatin in comparison with the control (first day, EA1 vs. Control, 1.0±0.2 vs.1.9±0.3g, p=0.017; second day, 0.4±0.2 vs.1.1±0.3g, p= 0.010); 3) Treatment with EA2 had no effects on kaolin intake after Cisplatin. Conclusions: Electrical stimulation via chronically implanted electrodes at acupoints is feasible. That is, EA may be performed chronically and continuously using implantable electrodes and pulse generator. EA at PC6 with appropriate parameters is able to reduce Cisplatin-induced kaolin intake in rats, suggesting an ameliorating effect on chemotherapy-induced emesis. The significant difference in the performance of EA with different parameter sets demonstrates the importance of parameter optimization in the application of EA.

S2076 A Novel Method of Electrical Stimulation via Electrodes Chronically Implanted at Acupoints and Its Effect on Cisplatin-Induced Emesis in Rats Assessed by Pica

Background and Aims: Acupuncture or electroacupuncture (EA) has been applied for treating chemotherapy-induced emesis with limited success. Two major problems with EA include infrequent application of EA and suboptimal stimulation parameters. The aims of this study were to investigate the feasibility of EA using chronically implanted electrodes and the effects of EA with different parameters on cisplatin-induced emesis in rats assessed by pica (intake of kaolin) that has been validated as a surrogate of emesis in rats. Materials and Methods: Under anesthesia, 19 SD rats were chronically implanted with a pair of electrodes at bilateral acupoint PC6 as follows: A 3mm tip of the exposed wire (serving as an electrode) was inserted into the acupoint and the connecting wire was firstly fixed in the muscle layer around the acupoint, then tunneled subcutaneously to the back of the neck and finally exited and protected for EA. After recovery and appropriate acclimation, the rats were treated using a 3×3 Latin Square cross-over design in which each rat received a sequence of 3 treatments in one of 3 assigned orders. The treatments included the following: EA1: 20Hz, 0.6ms, 2mA and continuous stimulation; EA2: 10Hz, 1.2ms, 2mA and continuous stimulation; Control: no stimulation. During each treatment, cisplatin 6mg/kg was injected intraperitoneally at 3PM during the first day and the rats received with one of the three treatments while staying at a rat restrainer for 3 hrs from 6pm-9m daily for 2 days. During the other periods, the rats were housed in their individual cages. There was an interval of 2 weeks between the two consecutive treatments. Results: 1) The implanted electrodes remained secured at the acupoints without infections. 2) Cisplatin induced substantial kaolin intake as well as reduced food intake and body weight; Treatment with EA1 significantly reduced kaolin intake on the first and second day after cisplatin in comparison with the control (first day, EA1 vs. Control, 1.0±0.2 vs.1.9±0.3g, p=0.017; second day, 0.4±0.2 vs.1.1±0.3g, p= 0.010); 3) Treatment with EA2 had no effects on kaolin intake after Cisplatin. Conclusions: Electrical stimulation via chronically implanted electrodes at acupoints is feasible. That is, EA may be performed chronically and continuously using implantable electrodes and pulse generator. EA at PC6 with appropriate parameters is able to reduce Cisplatin-induced kaolin intake in rats, suggesting an ameliorating effect on chemotherapy-induced emesis. The significant difference in the performance of EA with different parameter sets demonstrates the importance of parameter optimization in the application of EA.

Brain encoding of acupuncture sensation — Coupling on-line rating with fMRI

Acupuncture-induced sensations have historically been associated with clinical efficacy. These sensations are atypical, arising from sub-dermal receptors, and their neural encoding is not well known. In this fMRI study, subjects were stimulated at acupoint PC-6, while rating sensation with a custom-built, MR-compatible potentiometer. Separate runs included real (ACUP) and sham (SHAM) acupuncture, the latter characterized by non-insertive, cutaneous stimulation. FMRI data analysis was guided by the on-line rating timeseries, thereby localizing brain correlates of acupuncture sensation. Sensation ratings correlated with stimulation more (p<0.001) for SHAM (r=0.63) than for ACUP (r=0.32). ACUP induced stronger and more varied sensations with significant persistence into no-stimulation blocks, leading to more run-time spent rating low and moderate sensations compared to SHAM. ACUP sensation correlated with activation in regions associated with sensorimotor (SII, insula) and cognitive (dorsomedial prefrontal cortex (dmPFC)) processing, and deactivation in default-mode network (DMN) regions (posterior cingulate, precuneus). Compared to SHAM, ACUP yielded greater activity in both anterior and posterior dmPFC and dlPFC. In contrast, SHAM produced greater activation in sensorimotor (SI, SII, insula) and greater deactivation in DMN regions. Thus, brain encoding of ACUP sensation (more persistent and varied, leading to increased cognitive load) demonstrated greater activity in both cognitive/evaluative (posterior dmPFC) and emotional/interoceptive (anterior dmPFC) cortical regions. Increased cognitive load and dmPFC activity may be a salient component of acupuncture analgesia — sensations focus attention and accentuate bodily awareness, contributing to enhanced top-down modulation of any nociceptive afference and central pain networks. Hence, acupuncture may function as a somatosensory-guided mind–body therapy.

Effects of acupuncture on chronic corticosterone-induced depression-like behavior and expression of neuropeptide Y in the rats

Repeated injection of corticosterone (CORT) induces dysregulation in the HPA axis, resulting in depression and anxiety. Many studies have shown that acupuncture, which is widely used for the treatment of stress and mental illness, in East Asian countries, is an effective therapeutic intervention for psychosomatic disorders. We investigated the influence of acupuncture therapy on chronic CORT-induced behavioral responses to the forced swimming test (FST) and elevated plus maze (EPM) and expression of neuropeptide Y (NPY) in the rat brain using immunohistochemistry. Male Sprague-Dawley rats were injected with CORT (40mg/kg, i.p.) once daily for 19 consecutive days. The dysregulation of HPA axis by external injection of CORT was confirmed by measuring the CORT concentration in plasma and the expression level of CRF in hypothalamus. Acupuncture was performed at the PC6 acupoint for 5min before CORT injection. Acupuncture significantly reduced depression- and anxiety-like behavior and increased NPY expression in the hypothalamus. These results demonstrated that stimulation of the PC6 acupoint suppresses the symptopathology of the hypoactivated HPA axis in chronic CORT-induced rat model of depression.

Effects of Acupuncture Stimulation on Recovery Ability of Male Elite Basketball Athletes

Developing effective methods for helping athletes recover from muscle fatigue is deemed essential, particularly on the eves' important competitions. This study aimed to investigate the effects of acupuncture stimulation on athletes' recovery abilities. Subjects were selected from 30 male elite university basketball players who were randomly assigned to 3 groups: acupuncture group, sham group, and normal (control) group, each containing 10 subjects. Acupuncture was carried out on each athlete in acupuncture group at the Neiguan (PC6) and Zusanli (ST36) acupoints, beginning at 15 min prior to exercise and continuing until exhaustion of the subject. Similar acupuncture was also carried out on each athlete in the sham group but the positions were 1 cm away from the PC6 and ST36 acupoints. No acupuncture was conducted on the athletes in the normal group. During the experiments, each subject performed separate runs on the treadmill. The data of heart rate (HR(max)), oxygen consumption (VO(2max)), and blood lactic acid were measured during the rest period and at 3 recovery points of time (5th, 30th and 60th min) post-exercise. The results showed that the acupuncture group (PC6 and ST36) has significantly lower HR(max), VO(2max) and blood lactic acid than both the sham and normal groups at the 30th min post-exercise. Blood lactic acid of the acupuncture group was also significantly lower than that of the other two groups in the 60th min post-exercise. Our findings have shed some light on the development of effective acupuncture schemes to enhance the recovery ability for elite basketball athletes.

Transcutaneous Electrical Nerve Stimulation at the PC-5 and PC-6 Acupoints Reduced the Severity of Hypotension After Spinal Anesthesia in Patients Undergoing Cesarean Section

Transcutaneous Electrical Nerve Stimulation at the PC-5 and PC-6 Acupoints Reduced the Severity of Hypotension After Spinal Anesthesia in Patients Undergoing Cesarean Section

Spatiotemporal Mapping the Neural Correlates of Acupuncture with MEG

Acupuncture is an ancient Eastern healing modality with putative therapeutic applications. Unfortunately, little is known about the central mechanisms by which acupuncture may exert its effects. In this study, 16 [corrected] healthy subjects were evaluated with magnetoencephalography (MEG) to map the location and timing of brain activity during low-frequency electroacupuncture (EA) and mechanical, noninsertive, sham acupuncture (SA) given at acupoint PC-6. Both EA and SA evoked brain responses that localized to contralateral primary somatosensory (SI) cortex. However, initial responses for EA peaked slightly earlier than those for SA and were located inferiorly within SI. Average equivalent current dipole strength was stronger (particularly at latencies >60 ms) for SA. These spatiotemporal differences between activations elicited by EA and SA are likely attributable to stimulus modality (electrical versus mechanical) and differences in the underlying somatosensory fibers transmitting these signals. The present data confirm that acupuncture modulates activity within somatosensory cortex, providing support for previous studies that suggest that the therapeutic effects of acupuncture are linked to SI modulation. Thus, MEG provides excellent spatiotemporal characterization of the somatosensory component of acupuncture, and future studies can contrast derived brain response parameters in healthy controls with those found in a diseased state.

Transcutaneous electrical nerve stimulation at the PC-5 and PC-6 acupoints reduced the severity of hypotension after spinal anaesthesia in patients undergoing Caesarean section

Despite prophylactic measures, hypotension remains a common side-effect of spinal anaesthesia for parturients. Electroacupuncture at the Neiguan (PC-6) and Jianshi (PC-5) points influences haemodynamics. We thus hypothesized that transcutaneous electrical nerve stimulation (TENS) at traditionally used acupuncture points would reduce the severity of hypotension after spinal anaesthesia in patients undergoing Caesarean section. After obtaining approval from the local ethics committee and written informed patient consent, 36 singleton parturients undergoing Caesarean section under spinal anaesthesia were randomized into three groups. The control group received no treatment, and the acupoint and non-acupoint groups received TENS at the PC-5 and PC-6 points of both arms and non-acupoints of both shoulders, respectively. The median (range) of the lowest recorded systolic blood pressure was significantly higher in the acupoint group compared with the other groups and that of the non-acupoint group was higher than that of the control group [control, 70 (68-82) mm Hg; acupoint, 94 (84-109) mm Hg; non-acupoint, 81 (70-92) mm Hg: P<0.001]. Significantly more parturients in the control and non-acupoint groups experienced hypotension [control, 10 (83%); acupoint, 4 (33%); non-acupoint, 10 (83%): P=0.013]. More ephedrine was required to maintain arterial blood pressure in the control and non-acupoint groups. TENS on the traditional acupuncture points reduced the severity and incidence of hypotension after spinal anaesthesia in parturients.