Editor's Choice—Specificity of acupuncture acupoints:observation by functional magnetic resonance imaging

Acupuncture at certain acupoints （specific sites for needle insertion） can induce the activation of specific regions of the brain. This activated brain region influences the target organ or tissue in order to treat the disease. Acupoint specificity is the basis of acupuncture therapy.

Mechanisms of electroacupuncture effects on acute cerebral ischemia/reperfusion injury:possible association with upregulation of transforming growth factor beta 1

Electroacupuncture at the head acupoints Baihui（GV20） and Shuigou（GV26） improves recovery of neurological function following ischemic cerebrovascular events,but its mechanism remains incompletely understood.We hypothesized that the action of electroacupuncture at these acupoints is associated with elevated serum levels of transforming growth factor beta 1（TGF-β1）.To test this,we established a rat model of cerebral ischemia by middle cerebral artery occlusion.Electroacupuncture was performed at Baihui and Shuigou with a “dispersedense” wave at an alternating frequency of 2 and 150 Hz,and at a constant intensity of 3 m A.Each electroacupuncture session lasted 30 minutes and was performed every 12 hours for 3 days.Neurological severity scores were lower in injured rats after acupuncture than in those not subjected to treatment.Furthermore,serum level of TGF-β1 was greater after electroacupuncture than after no treatment.Our results indicate that electroacupuncture at Baihui and Shuigou increases the serum level of TGF-β1 in rats with acute cerebral ischemia/reperfusion injury,and exerts neuroprotective effects.

Magnetic stimulation at Neiguan(PC6) acupoint increases connections between cerebral cortex regions

Stimulation at specific acupoints can activate cortical regions in human subjects.Previous studies have mainly focused on a single brain region.However,the brain is a network and many brain regions participate in the same task.The study of a single brain region alone cannot clearly explain any brain-related issues.Therefore,for the present study,magnetic stimulation was used to stimulate the Neiguan（PC6） acupoint,and 32-channel electroencephalography data were recorded before and after stimulation.Brain functional networks were constructed based on electroencephalography data to determine the relationship between magnetic stimulation at the PC6 acupoint and cortical excitability.Results indicated that magnetic stimulation at the PC6 acupoint increased connections between cerebral cortex regions.

Central neuromechanisms underlying control of intragastric pressure through acupuncture at Zusanli(ST36) in rats: the upper cervical cord is the key link between the ascending and descending pathways

Sensory inputs stimulated by Zusanli（ST36） acupuncture in the abdomen are known to converge in the upper cervical cord. However, it is unclear whether these inputs are subsequently conveyed to the hypothalamic paraventricular nucleus and what kind of afferent fibers are involved. We focused on the upper cervical cord, where afferent inputs converge, and detected c-fos expression in oxytocinergic neurons. We found that Zusanli acupuncture therapy effectively elevated intragastric pressure, but inhibited expression of c-fos in oxytocinergic neurons of the paraventricular nucleus in upper cervical cord injured rats. These Zusanli acupuncture effects remained even after complete dorsal cord transection. However, after complete transection of the spinal cord or dorsolateral funiculus, the effects were significantly attenuated and even disappeared. These findings suggest that the paraventricular nucleus is responsible for pooling and integrating signals from the Zusanli acupuncture and sensory information from the intragastric pressure variation, thereby contributing to the regulation of intragastric pressure. The upper cervical cord serves as the key link between ascending and descending pathways, which conveys afferent inputs to the paraventricular nucleus through the dorsolateral funiculus.

ACUTE WAIST SPRAIN TREATED BY ACUPUNCTURING DONGSHI ACUPOINT

Acute waist sprain is a local injury of themuscle, fascia and ligament in the waist due tosudden overstretch by external force beyond thenormal physiological limit. Acute waist spraincan lead to cicatrix adhesion, loss of normal tis-sue function and chronic waist pathologicalchanges without timely and effecthe treatment.Long time treatment without cure will affectboth work and daily life.

Nitric Oxide Signaling Molecules in Acupoints:Toward Mechanisms of Acupuncture

Recent clinical trial studies have demonstrated that the effects of acupuncture on pain improvement are small and no difference between acupoints and non-points. Whether acupuncture needles must be inserted in specific points depends on whether acupoint specificity exists that is still not resolved, and is now urgent. Previous anatomical studies have demonstrated that acupoints exist higher number of nerve fibers/trunks, blood vessels, hair follicles, and sweat glands as well as density of the gap junction. Recent evidence shows that nitric oxide（NO） level is elevated in the acupoints/meridians and is associated with an enhanced expression of NO synthase endowed with transient receptor potential vanilloid type-1. There is growing evidence from international groups showing that acupuncture induces NO-mediated vasodilatation, which increases local blood flow and allows for a flush of algesic or sensitizing substances, leading to pain relief. Previous studies, using a novel biocapture system, have demonstrated that NOx–（total nitrite and nitrate） and cyclic guanosine monophosphate（c GMP） concentrations are consistently increased over skin acupoints compared to non-meridian control regions（NMCR） in humans. Dermal microdialysis in humans showed that NO-c GMP releases in the subcutaneous tissue of acupoint are higher than those in NMCR and increased by electroacupuncture（EA）. Recent studies have demonstrated that low-frequency electrical stimulation and manual acupuncture with low stimulating force and rate produce an elevation of NO release predominantly over acupoints. In contrast, NO levels over the areas of the skin regions are moderately reduced by high-frequency EA stimulation. The results from anatomical and biochemical studies consistently show that acupoints exist higher levels of NO signaling molecules, and stimulus-evoked NO release is also with a higher level at acupoints. Results suggest that NO signaling molecules contribute to the specificity of acupoints, and selecting well-trained acupuncturetists for using correct acupoints and appropriate parameters should improve acupuncture clinical trial studies.