[Research advances in the limbic system involved in acupuncture treatment of chronic pain].

Pain, especially chronic pain, can cause multiple changes including sensory-discriminative, emotional-affective, and cognitive-behavior changes and thus greatly affects patients' physical and mental health and quality of life. Therefore, multi-dimensional regulation of paralgesia, cognitive impairment, and negative emotion in patients with chronic pain has become a hot spot in recent studies. The brain regions in the limbic system are involved in the formation and expression of "pain sensation-emotion-cognition". Existing evidence suggests that acupuncture has a multi-dimensional comprehensive regulatory effect on chronic pain, and the brain regions in the limbic system also mediate the analgesic effect of acupuncture. However, further studies are still needed to explore the role and mechanism of action of these brain regions in the multi-dimensional regulation of chronic pain by acupuncture. This article reviews the research advances in the neural mechanism of the limbic system in chronic pain and the role of the limbic system in mediating acupuncture analgesia and mainly elaborates on the mechanism of action of the brain regions in the limbic system in the multi-dimensional regulation of chronic pain.

[Electroacupuncture Relieves Pain by Down-regulating Expression of Hippocampal High Mobility Group Protein 1 and Contents of TNF-α and IL-1 ß in Rats with Chronic Neuropathic Pain].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on expression of high mobility group protein 1 (HMGB 1) and related downstream effectors of proinflammatory cytokines in the hippocampus in chronic neuropathic pain rats, so as to investigate its mechanism underlying neuropathic pain relief. METHODS: Male SD rats were randomized into sham, model, and EA groups, with 12 rats in each group. The neuropathic pain model was established by ligature of the left sciatic nerve to induce chronic constriction injury (CCI). EA was applied to bilateral "Zusanli"(ST 36) and "Yanglingquan"(GB 34) for 30 min, once daily for 7 days. The mechanical withdrawal threshold (WMT) was detected using an electronic von Frey anesthesiometer. The expression level of HMGB 1 in the hippocampus was determined using quantitative RT-PCR and Western blot, separately, and the contents of hippocampal TNF-α and IL-1 ß were detected by ELISA. RESULTS: Compared with the sham group, the MWT values were markedly decreased on day 7, 10 and 14 after modeling in the model group (P<0.001). On day 10 and 14 after modeling, the MWT values were significantly up-regulated in the EA group relevant to those of the model group (P<0.05, P<0.01). The expression levels of HMGB1 mRNA and protein, and the contents of hippocampal TNF-α and IL-1 ß were markedly increased in the model group relevant to the sham group (P<0.001), and significantly down-regulated in the EA group relevant to the model group (P<0.001, P<0.01, P<0.05). CONCLUSION: EA stimulation of ST 36-GB 34 can relieve pain in chronic neuropathic pain rats, which may be related to its actions in down-regulating the levels of HMGB 1 and its downstream proinflammatory cytokines TNF-α and IL-1 ß in the hippocampus.

[Research on Acupuncture in Regulating the Inflammatory Reaction in Anti-ischemia-reperfusion Injury].

The inflammatory response during ischemia-reperfusion is one of principal reasons for secondary organ injury. Therefore, the inhibition of inflammation has become a research hot spot. The current research showed that acupuncture can not only directly inhibit the infiltration of inflammatory cells and regulate the expression of inflammatory cytokines, but is also involved in the overall regulation of the inflammatory signaling pathway and inhibition of the inflammatory response, thereby effectively improving ischemia-reperfusion injury. Here, we review research on the mechanism of acupuncture in ischemia-reperfusion injury via regulation of the inflammatory response.