| BackgroundAcupuncture, a significant and mystical therapy of Traditional Chinese Medicine (TCM), has been commonly used to treat various diseases for thousands of years. Acupuncture is easy to operate, low cost and curative effect, has become one of the world’s most widely used alternative medicine. Since ancient times, a number of methods have been used to understand the mechanisms of acupuncture. However, a full comprehension has not yet been achieved. This greatly affected the further promotion and application of acupuncture and moxibustion in the world.In recent decades, the application of imaging techniques such as positron emission tomography (PET) and functional magnetic resonance imaging (FMRI) have provided practical methods to explore the mechanisms of acupuncture treatment and visually identify connections within the brain, which is crucial to the mechanism of acupuncture. Given the previous successful application of imaging technology in clinical studies of acupuncture, the specificity of meridians and acupoints has become an important topic, and its specificity has been partly confirmed by numerous studies. However, the specificity of acupuncture stimulation requires further elucidation.Effect of acupuncture point specificity refers to the corresponding response produced by the body to stimulate the acupuncture point appropriate, relative to stimulate the acupuncture point or other acupuncture point caused by the reaction of specificity.Although in recent years, many scholars at home and abroad for extensive and in-depth research was conducted on the effect of acupuncture point, but in the meridian specificity is still controversial whether there is any effect.Modern medical studies have shown that acupuncture point and specific brain cortex function is closely related to acupuncture point and the effect of the key hub between target organ is the brain, acupuncture meridian as a stimulus should be carried out after the brain central adjustment and integration, and then applied to target organs, resulting in a treatment effect.fMRI provides a new technology for research of the specificity, curative effect and mechanism of acupuncture and meridian research.Design method of commonly used FMRI experiments including task-state and resting-state interest. The resting-state FMRI is superior to the task design because of its simple design, easy to control, baseline researchable continuous neural activity. Resting-state refers to the participants to stay awake, do not accept any external stimulation, or perform any advanced features, eliminates the task state subjects in the study of the individual to perform a task difference influence on the results of the study. In the resting state FMRI study, a large number of brain connections information can be obtained by choosing different methods of analysis. In FMRI studies, two major methods are widely used for characterizing the regional properties, namely, "Amplitude of Low-Frequency Fluctuation" (ALFF) and "Regional Homogeneity" (ReHo). Either method can reveal changes in brain activity among certain brain regions. ReHo analysis reflect the consistency of partial function of time sequence, provide a new method for the central research of acupuncture and mechanism. Due to the superiority of ReHo, this analysis has been applied to study Alzheimer’s disease, Parkinson’s disease, migraines, attention-deficit/hyperactivity disorder, Mild Cognitive Impairment (MCI), and other conditions. The utilization of ReHo has become a global trend in acupuncture research. Therefore, we applied ReHo as an analytical tool in our study using healthy volunteers as subjects, and we were able to identify the active or inactive brain areas.Acupoints are reactive positions of diseases on the surface of the body and the crucial components of acupuncture based on the theories of TCM and acupuncture, the objective of which is obtaining close relationships among meridians, specific visceral organs7-and the spirit, which is stored in the brain. Theoretically, acupoints are intended to act as a point of penetration, and therefore, many studies have chosen acupoints such as LR3, SJ5, ST36, and GB34 to investigate the effects of acupuncture on brain function using FMRI. Based on previous research, it is clear that the selection of single acupoints puts greater emphasis on the specific acupoints than the combination of other points; however, in TCM theory, a combination of acupoints, particularly a unique combination, is expected to produce special effects. In a majority of studies, acupoints are selected in pairs or in groups that tend to connect with the corresponding diseases, although either the functions or the empirical clinical applications do not completely match with TCM theories. According to the "Miraculous Pivot", a famous ancient Chinese medical work, "the Qi of meridian gathers together into He-sea points" is an important description of these cases.This indicates that the combination of He-sea points would more clearly illustrate the effects of acupuncture treatment. To confirm the theory that acupuncture at pairs of acupoints would be more effective than at a single acupoint, we selected the Zusanli (ST36) and Yanglingquan (GB34) acupoints, which are the He-sea points of the Yangming Stomach Meridian the Shaoyang Gallbladder Meridian, respectively. In addition, some studies have indicated that the combination of the Zusanli and Yanglingquan acupoints possesses a therapeutic effect in certain diseases. Although ST36 and GB34 differ in their meridian categories, they belong to the L5 dermatome skin areas, which means that they share the same nerve innervations and the same histological type. Whether these acupoints possess some special connection requires further study regarding brain activity and the multiple effects of ST36 and GB34 in clinical practice, which could provide evidence for their combined use in clinical practice.Acupuncture treatment mechanism may be similar to reflex arc, including acupuncture, incoming, central activation, and effect, in which central effect may be the key link, can more fully to clarify its mechanism of action. We utilized FMRI to test the hypothesis that acupuncture stimulation at pairs of acupoints would produce brain activation or deactivation in several regions, and that, compared with single acupoints, it would activate or deactivate additional functional regions that would not be affected by single acupoints. We designed our study to apply the ReHo method in healthy volunteers to observe acupuncture stimulation at both ST36 and GB34 using resting-state FMRI compared with acupuncture stimulation at ST36 and GB34 separately, in order to clarify its central effects of acupuature at ST36 and GB34 and provide the evidences for acupoints compatibility medicine application.Objective1. To explore the mechanism of acupuncture points by observe Regional Homogeneity of resting state of brain function after acupuncture at zusanli(ST36).2. To explore the mechanism of acupuncture points by observe Regional Homogeneity of resting state of brain function after acupuncture at zusanli(GB34).3. This study aimed to observe the cerebral activation effects of acupuncturing the Zusanli (ST36) plus Yanglingquan (GB34) points in young healthy volunteers based on Regional Homogeneity (ReHo) indices.Materials and Methods1. Clinical DataThis study included 10 healthy volunteers consisting of 4 males and 6 females between the ages of 20 to 34 years old, with a median age of 23 years. All of the volunteers were previously healthy, had not taken drugs or undergone acupuncture within the last month, had no MRI contraindications and had signed informed consent forms.2. Equipment and TechniquesThe following apparatus and equipment were used:0.32 mm×40.00 mm disposable sterile acupuncture needles (Tianxie Acupuncture Instruments Corporation in Suzhou); a Signa HDxt 3.0T MRI scanner manufactured by GE organization; and an MRI chamber located at (ellipsis)3. Experimental Design and Data Collection3.1 Acupuncture methodsThe puncture was performed by one highly qualified acupuncture doctor. The acupoints were the left GB34 and the left ST36. Manipulation consisted of puncture for 15 min after getting a needle reaction and a twist of the needle once every 2 min (10 s each twist). The brains were scanned immediately after finishing the acupuncture.Imaging design for resting-state cerebral functionResting-state FMRI data as well as two-dimensional (two-dimensional,2D) and three-dimensional (three-dimensional,3D) anatomical image data were collected for the four groups. The scanning interval for each group was 24 hours.3.3 MRI ScanQuadrature coil neck coil. The volunteers were in a supine position on the examination bed, were awake with calm breathing, and had no proactive thinking movement but were informed of the scanning environment in advance. A foam pad was used to fix the head, and rubber earplugs were used to reduce the noise. Scanning steps:Structural positioning imaging, fast spin echo sequence (FSE) and axial T1-weighted fluid-attenuated inversion recovery (T1-FLAIR) were used to perform the scan, with the baseline parallel to the anterior and posterior combine-line (AC-PC) of the corpus callosum. A total of 28 slices covering the entire brain were acquired. Resting-state blood oxygenation level dependent (BOLD) imaging, echo planar imaging (EPI) sequence and T1-FLAIR image positioning were used with the same number of scanning layers to structurally position the image, and 8400 images were obtained. A high-resolution image of the entire brain scan, including a three-dimensional structure used for brain volume imaging (BRAVO) sequences, was constructed and used to obtain 136 images. The parameters of each sequence scan are listed in Table 1.4. Data processing and fMRI statistics4.1 Data preprocessingThe original image was input to an offline workstation. The package for statistical parametric mapping software (SPM8, http://www.fil.ion.ucl.ac.uk/spm/), which is run using MATLAB2009b, and a software package based on SPM8 and DPARSF of REST 1.2 were used. The main steps were as follows:The first 10 images were removed to exclude effects due to the time required for the magnetic fields to reach the steady state and for the volunteers to adapt to the environment. Time correction:this step aimed to reduce the differences of the moment to obtain each picture. Head movement correction:this step aimed to reduce the effect of signals due to the noise generated by the movement of the head. Data corresponding to the three-dimensional translation of the head moving> 1 mm and a three-dimensional rotation> 1° were removed. Spatial normalization:the functional sequence of the images of all of the volunteers is spatially normalized to the Montreal Neurological Institute (MNI) template to locate the active region of the brain. Spatial smoothing:all normalized data were processed using Gaussian smoothing, i.e., processed data were convoluted with an isotropic Gaussian kernel using a full width half maximum (FWHM) of 8 mm to improve the image quality. Low-pass filtering:the obtained signal was subjected to low-pass filtering of 0.01～0.08 Hz to remove the interference generated by high- and low-frequency signals. Finally, the obtained frequency wave signals were analyzed using ReHo.4.2 ReHo analysis:Resting state FMRI data analysis toolkit (REST), which is a software developed by the National Key Laboratory of Cognitive Neuroscience and Study of Beijing Normal University (more information at http://sourceforge.net/projects/resting-fMRI), was adopted for ReHo analysis. Consistency in the time series of every voxel with its adjacent voxel in the brain was calculated to obtain the Kendall’s coefficient of concordance (KCC). The KCC was the ReHo of the voxel, and the ReHo of every voxel constituted the subjects’ ReHo brain. The following Equation (1) for the KCC for a fixed point was used: where W is the KCC of a fixed point with the range 0-1; n is the time point (n=250 in this study); K is the total number of given voxels with their adjacent voxel point (K=27 in the study), i.e., the given point itself and its 26 adjacent points comprise a voxel cluster;Ri is the total level of the voxel values of 27 points at the ith time point; and R is the mean of Ri.104.3 Image viewingBrain images that were statistically significant after the above processing were superimposed on standard brain images to obtain images that displayed anatomical and statistical information, including image information for the sagittal, coronal, horizontal position or 3D mode images. Figure plugins such as Slice Viewer and Xjview were used to read the coordinates of the activated brain areas, the anatomical location and the T values in the MNI template.5. Statistical MethodsStandardized ReHo brain diagrams of the Compatibility Group and every other group were obtained using a two-sample paired t-test with SPM8 software, with the results from two one-sample t-tests set used as a mask. In this context, the results were corrected for the false discovery rate (FDR). Significance was defined as P<0.05, T=2.262 and K>405. The regions of no significance, for which the voxel values were less than 10, were removed to obtain the difference in ReHo values for the cerebral areas pre- and post-puncture at GB34.Results1. Cerebral ReHo differences between the ST36 Group and the Control GroupRight anterior cingulated gyrus, left middle frontal gyrus enhance ReHo after acupuncture at zusanli(ST36).Left cerebellar hemisphere, right posterior cingulated gyrus, left putamen, right insular cortex, left side of the corpus callosum, left precuneus, right medial frontal decrease ReHo after acupuncture at zusanli(ST36).2. Cerebral ReHo differences between the GB34 Group and the Control GroupCompared with control group, the anterior cingulated gyrus, left temporal gyrus, right inferior parietal lobule, right frontal gyrus were enhanced ReHo after acupuncture at Yanglingquan(GB34). The left thalamus, right insular cortex, left inferior frontal gyrus, right anterior cingulate were decreased ReHo after acupuncture at Yanglingquan(GB34).3. Cerebral ReHo differences between the Compatibility Group and the Control GroupThe ReHo results demonstrated that left side of the internal capsule, right frontal lobe white matter, the left and right frontal white matter cingulate were increased in the Compatibility Group compared with the pre-acupuncture condition. In contrast, the results in the right cerebellum posterior lobe, left the precuneus, the left precentral gyrus and right inferior frontal gyrus were decreased.4. Differences in cerebral ReHo values between the Compatibility Group and the ST36 GroupThe ReHo results demonstrated that the left inferior parietal lobule (BA40) and the right frontal cortex (BA6) were increased in the Compatibility Group compared with the ST36 Group (Table 4), whereas the values in the left occipital lobe cortex (BA19) and the left inferior frontal gyrus (BA9) were decreased.5. Differences in cerebral ReHo values between the Compatibility Group and the GB34 GroupThe results demonstrated that the ReHo values of the posterior lobe of the right cerebellum, the dorsal anterior cingulate (BA32), the left middle frontal gyrus (BA46), the left precuneus (BA7), the right middle frontal gyrus (BA9) and the right inferior parietal lobe (BA40) were increased in the Compatibility Group compared with GB34 Group (Table 6), whereas the values of the left insular lobe (BA13) and the left paraventricle white matter were decreased.Conclusion1. Acupuncture at Zusanli(ST36) can cause ReHo changes of cerebrum, cerebellum, corpus callosum, the limbic system, and other brain regions, suggesting that brain effect caused by acupuncture at ST36 is a complex process that may be multiple brain regions by brain network comprehensive work.2. Acupuncture at Yanglingquan(GB34) can cause ReHo changes in many brain regions including cognition, motion, default network and the limbic system, suggesting that brain regions acitivated by acupuncture at GB34 has certain relationship with efficacy of GB34, and its central mechanisms may be at all levels of brain function network synthesis.3. The results of our neuroimaging study suggest that the combination of acupoints could more widely activate areas of the brain compared to a single acupoint. Additionally, the combination of acupoints can activate some new brain areas and generate new curative effects. |
PDF Full Text Request