Xin-Yan Gao

Investigation of specificity of auricular acupuncture points in regulation of autonomic function in anesthetized rats.

Auricular acupuncture has been used for various autonomic disorders in clinical practice. It has been theorized that different auricular areas have distinct influence on autonomic functions. The present study aims to examine the effects of acupuncture stimulation at different auricular areas on cardiovascular and gastric responses. In male Sprague-Dawley rats anesthetized with pentobarbital sodium, five auricular areas, which were located at the apex of the helix (A(1)), the middle of the helix (A(2)), the tail of the helix (A(3)), the inferior concha (A(4)) and the middle of the antihelix (A(5)), had been selected for stimulation with manual acupuncture (MA) and different parameters of electroacupuncture (EA). A mild depressor response (6%-12% decrease from baseline) was evoked from A(1), A(3) and A(4) by MA and from all five areas by EA (100 Hz-1 mA). The biggest depressor response (-18.4+/-3.1 mmHg, p<0.001) was evoked from A(4). A small bradycardia was evoked by MA from A(4) and by EA at A(3), A(4) and A(5.) Increase in intragastric pressure (8-14 mmH(2)O) was evoked by MA from A(1), A(3) and A(4) and by EA at A(2.) These results show that similar patterns of cardiovascular and gastric responses could be evoked by stimulation of different areas of the auricle. The present results do not support the theory of a highly specific functional map in the ear. Rather, there is a similar pattern of autonomic changes in response to auricular acupuncture, with variable intensity depending on the area of stimulation.

A C-fiber reflex inhibition induced by electroacupuncture with different intensities applied at homotopic and heterotopic acupoints in rats selectively destructive effects on myelinated and unmyelinated afferent fibers

The aims of this study were to explore the C-fiber reflex inhibition induced by electroacupuncture with different intensities applied at homotopic or heterotopic acupoints, and to determine the influence selectively destroyed myelinated and unmyelinated afferent fibers on the C-fiber reflex inhibition. In the ipsilateral local acupoint, the general behavior of the C-fiber reflex can be depressed by electroacupuncture below the threshold of Adelta-fiber activation. Electroacupuncture stimulation within the intensity of Adelta-fiber activation applied to the ipsilateral limb pretreated with cobra venom did not elicit inhibition of C-fiber reflex in rats with demyelinated sciatic nerve. However, heterotopic electroacupuncture below the threshold of Adelta-fiber activation was totally ineffective. In contralateral heterotopic acupoints, the C-fiber reflex can be depressed only by electroacupuncture with stimulating intensities exceeding thresholds of Adelta and C-fiber activation. Electroacupuncture stimuli applied to capsaicin-pretreated limb in the intensities of threshold of Adelta-fiber and treble thresholds of C-fiber activation produced only a little inhibition of C-fiber reflex. Inhibitory intensity was roughly similar to that induced by the stimulation with intensity for the activation of Adelta-fiber in normal animal. In the spinalized animals transections at T6-T7 segments, regardless of intensities, the homotopic electroacupuncture stimulation only induced moderate depression of C-fiber reflex similar to that of Adelta-fiber activation; whereas, no matter what intensities of application, the inhibitory effects of C-fiber reflex disappeared totally by using heterotopic noxious electroacupuncture in these animals.

Acupuncture-like stimulation at auricular point Heart evokes cardiovascular inhibition via activating the cardiac-related neurons in the nucleus tractus solitarius.

Fifty-eight male Sprague-Dawley rats used in the present study to investigate the role of baroreceptor sensitive neurons of the nucleus tractus solitarius (NTS) in the regulation of cardiovascular inhibition during acupuncture at the auricular point Heart, single unit recording was made in anesthetized Sprague-Dawley rats. A neuron was considered to be excited or inhibited by acupuncture stimulation if it displayed 15% more or less spikes s(-1), respectively. NTS neurons were classified into cardiac-related (CR) neurons and non-cardiac-related neurons based on whether their rhythmic discharges were synchronized with the R-waves and responding to sodium nitroprusside (NP; 20 μg/kg, i.v.) administration. Manual acupuncture was applied at the auricular point Heart and somatic acupuncture points ST36 and PC6. Acupuncture at auricular point Heart showed a more significant inhibitory effect on arterial pressure (-22.1±2.4mm Hg; P<0.001) and heart rate (-12.7±1.7 bpm; P<0.001) than that at ST36 and PC6. Acupuncture at auricular point Heart also increased the level of response of CR neurons in the NTS (93.8%±26.0% increase in discharge rate; P<0.01). Systemic or local administration of atropine attenuated the cardiovascular inhibition and activation of CR neurons evoked by auricular acupuncture, but had no effect on the same responses evoked by somatic acupuncture. Inactivation of the NTS with local anesthetics also decreased the cardiovascular inhibitory responses evoked by auricular acupuncture. Our results show that acupuncture at the auricular point Heart regulates cardiovascular function by activating baroreceptor sensitive neurons in the NTS in a similar manner as the baroreceptor reflex in cardiovascular inhibition.

Brain-Modulated Effects of Auricular Acupressure on the Regulation of Autonomic Function in Healthy Volunteers

Auricular acupuncture has been described in ancient China as well as Egypt, Greece, and Rome. At the end of the 1950s, ear acupuncture was further developed by the French physician Dr. Paul Nogier. The goal of this study was to develop a new system for ear acupressure (vibration stimulation) and to perform pilot investigations on the possible acute effects of vibration and manual ear acupressure on heart rate (HR), heart rate variability (HRV), pulse wave velocity (PWV), and the augmentation index (AIx) using new noninvasive recording methods. Investigations were performed in 14 healthy volunteers (mean age ± SD: 26.3 ± 4.3 years; 9 females, 5 males) before, during, and after acupressure vibration and manual acupressure stimulation at the “heart” auricular acupuncture point. The results showed a significant decrease in HR (P ≤ 0.001) and a significant increase in HRV total (P = 0.008) after manual ear acupressure. The PWV decreased markedly (yet insignificantly) whereas the AIx increased immediately after both methods of stimulation. The increase in the low-frequency band of HRV was mainly based on the intensification of the related mechanism of blood pressure regulation (10-s-rhythm). Further studies in Beijing using animal models and investigations in Graz using human subjects are already in progress.

The pain-relieving effects induced by electroacupuncture with different intensities at homotopic and heterotopic acupoints in humans.

The purpose of the present study was to investigate the relationship between the distribution of the analgesic area when different intensities of stimulation were applied to homotopic and heterotopic acupoints. The experiments were performed on volunteers; the left sural nerve was stimulated by a volley of eight rectangular pulses delivered at a frequency of 400 Hz. Electromyographic reflex responses (EMGs) were recorded from the ipsi-lateral biceps femoris muscle. Electroacupuncture stimuli were given on the skin overlying the Zusanli point (St 36), and the strengths chosen were times of the threshold eliciting a nociceptive reflex (T(RIII)) response (0.6, 0.8, 1.0, T(RIII) and T(supra-RIII), respectively). The effects of homotopic and heterotopic stimuli applied to St 36 on the pain sensation and the R(III), reflex elicited by stimulation of the left sural nerve were observed to explore the pain-relief and R(III) reflex-inhibition produced by stimulation of the St 36 point with different intensities. Both the nociceptive reflex and painful sensation evoked by stimulating the sural nerve were similarly inhibited by electroacupuncture at less than T(RIII) applied to the ipsi-lateral acupoint. In other words, acupuncture with an innocuous intensity can produce homotopic pain-alleviating effects and reflex suppression. With contra-lateral electroacupuncture at the St 36 acupoint, innocuous intensities cannot produce heterotopic pain-relieving effects; these inhibitions were only observed at electroacupuncture intensities similar to the T(RIII) threshold. These results suggest that local acupuncture-induced analgesia is effective with activation of large afferent fibers, whereas heterotopic acupuncture-induced analgesia is only effective with intensities strong enough to excite small afferent fibers. Local analgesic effects of acupoint stimulation involve segmental inhibition, whereas systemic analgesic effects of acupoint stimulation are involved in contra-lateral effects. The latter may recruit the diffuse noxious inhibitory controls (DNIC) system. The specific function of an acupoint is determined by the anatomical relationship between the disease focus and the segmental location of the acupoint.

Sino-European Transcontinental Basic and Clinical High-Tech Acupuncture Studies—Part 1: Auricular Acupuncture Increases Heart Rate Variability in Anesthetized Rats

Evidence-based research concerning the effects of high-tech acupuncture on autonomic function was performed by two research teams from China and Austria. This study describes the first transcontinental teleacupuncture measurements in animals. Heart rate (HR) and heart rate variability (HRV) recordings in 10 male Sprague-Dawley anesthetized rats were performed under stable conditions in Beijing, China, and the data analysis was completed in Graz, Austria. The electrocardiograms (ECGs) were recorded by an HRV Medilog AR12 system during acupuncture of the ear and body (PC6 Neiguan, CV12 Zhongwan, ST36 Zusanli). The data were analyzed using specially adapted novel Austrian software. HR did not change significantly during any acupuncture stimulation in anesthetized rats (ear acupuncture, PC6, CV12, or ST36). Total HRV only changed significantly (P = 0.025) during auricular acupuncture (acupoint heart). The low-frequency/high-frequency ratio parameter decreased significantly (P = 0.03) during stimulation of ST36. This change was based on intensification of the related mechanism of blood pressure regulation that has been demonstrated in previous studies in humans. Modernization of acupuncture research performed as a collaboration between China and Austria has also been demonstrated.

Mechanism of acupuncture regulating visceral sensation and mobility.

Chinese ancient medical scientists have long focused on the internal and external contacts between acupoints on the surface of the body and the viscera. The Miraculous Pivot (it is one of the earliest medical classics in China) stated, “Twelve regular channels belong to the zang-fu organs internally, and connect to the extremities and joints externally.” Traditional Chinese medicine considers acupoints as defined areas where the Qi of viscera and meridians are transfused. These include the reaction points of visceral diseases on the body surface as well as the acupuncture trigger points that promote the flow of Qi and blood, and regulate visceral function. Chinese ancient medical scientists classified the specificity of the main acupoints in the body based on the meridian doctrine, which has been instructing clinical application for about 2000 years. Laws on the domino effect of acupoints have mainly focused on conclusions to clinical experiences. Indications of some acupoints exceed the practical paradigm since the excessive extension occurred during theory derivation. The current research direction on acupuncture focuses on three aspects: the effectiveness of acupuncture and moxibustion; the relevances and associations between meridians and viscera; and the physical and chemical properties and relevant physical basis of acupoints. The relevance between meridians and viscera is the central theory in the meridian doctrine, and acupoints are regarded as an important link in the relationship between meridians and viscera. Specific relationships between acupoints and target organs exist. Stimulating different acupoints on the body surface can help deal with different diseases, especially visceral diseases. In addition, acupoints have a dual function of reflecting and treating visceral diseases. There is no systemic research available on acupoint specificity, despite current knowledge and clinical experiences, which results in a weak foundation for acupuncture theory. This study focuses on the relevance and associations between meridians and viscera. A summary of the mechanisms of acupuncture regulating visceral sensation and mobility and the specific relationships between acupoints and their target organs are presented in this review.

Sino-European Transcontinental Basic and Clinical High-Tech Acupuncture Studies—Part 3: Violet Laser Stimulation in Anesthetized Rats

The aim of this study was to determine the effect of violet laser stimulation on three acupuncture points in anesthetized rats and to test the hypothesis that violet laser light can modulate neurovegetative parameters like heart rate (HR), heart rate variability (HRV), and mean arterial blood pressure (MAP). Recordings were performed in 10 male anesthetized rats under three conditions in Beijing, and monitored with equipment from Graz, where also data analysis was performed. For stimulation a violet laser (emitted wavelength 405 nm, laser output 1 mW, continuous mode) was used. The electrocardiograms were recorded by an HRV Medilog AR12 system during laser acupuncture stimulation of the head, ear, and body (Baihui, “heart” ear acupoint, Zusanli). HR changed significantly only during (P = 0.013) and after (P = 0.038) stimulation at Baihui. Total HRV and the low frequency/high frequency ratio showed insignificant changes. There was an insignificant decrease in MAP after stimulation of Baihui acupoint. Violet laser stimulation offers a method to induce acute effects in HR and HRV in rats. Although the precise mechanism of this effect remains to be determined, alterations are significant. Violet laser stimulation on the Baihui acupoint could readily be translated to clinical studies.

Neurons in the nucleus tractus solitarius mediate the acupuncture analgesia in visceral pain rats.

The study investigated the role of nucleus tractus solitarius (NTS) neurons in electroacupuncture (EA) analgesia in colorectal distension (CRD) rats. NTS neurons responding to both CRD test and EA conditioning stimulations were considered somato-visceral convergent neurons. The neuronal activities evoked by graded CRD showed multiple firing patterns indicating multisynaptic connections. Some of the CRD excitatory neurons were inhibited by EA and vice versa. There was no discrepancy among different acupoints in inducing the changes of unit discharges. Conclusively, EA could regulate CRD related neurons in the NTS through polysynaptic cross-talk mechanism, which mediates EA analgesia on visceral pain in anesthetized rats.

The Effects of Scraping Therapy on Local Temperature and Blood Perfusion Volume in Healthy Subjects

Objective. We aim to study the therapeutic effects of scraping by investigating the changes of temperature and local blood perfusion volume in healthy subjects after scraping stimulation, and to explore the mechanism of scraping stimulation from the points of microcirculation and energy metabolism. Methods. Twenty-three health subjects were included in this study. Local blood perfusion volume and body surface temperature was detected at 5 min before scraping stimulation, 0, 15, 30, 60 and 90 min after scraping using Laser Doppler imager and infrared thermograph. Results. Significant increase was noted in the blood perfusion volume in the scraping area within 90 minutes compared to the baseline level and non-scraping area (P < 0.001). Compared with non-scraping area, an increase of body temperature with an average of 1°C was observed after scraping stimulation (P < 0.01). Conclusion. Scraping can significantly improve the blood perfusion volume and increase the temperature in the scraping area, promoting the local blood circulation and energy metabolism.