基于脊髓背角中枢敏化机制探讨腕踝针治疗慢性神经痛的镇痛作用

Wrist ankle acupuncture is a painless shallow needling method, which has a good analgesic effect on neuropathic pain. The occurrence .and development of neuropathic pain is closely related to central sensitization of spinal cord(abnormal neuronal excitation,glial activation and neuroinflammation in the dorsal horn of the spinal cord). The scientific hypothesis of this reserach is that the wrist ankle acupuncture might suppress spinal sensitization in the spinal cord of neuropathic pain for relieving the pain reaction. The main content of research is as follows: (1) Neuropathic pain would be induced according to the procedure described by Bennett and Xie (1988)，pain behaviors are used for observing the analgesic effect of wrist ankle acupuncture. The detection of spinal fMRI, PET-CTand molecular biology would be used for analyzing the spinal abnormal neuronal excitation and the expressing of Glu, 5-HT, β-EP, NMDA and their receptors.（2） Methods of immunohistochemistry and molecular biology would be used for detecting the glial activation and pro-inflammatory cytokines in the dorsal horn of the spinal cord. （3）Intrathecal injection of the receptor antagonist of NMDA,5-HT,β-EP would be applied for the effect of such neurotransmitters on the pain modulation and spinal abnormal neuronal excitation.The results of this study will reveal the central mechanism of the wrist ankle acupuncture analgesia, and provide an important basis for the clinical application of Wrist Ankle acupuncture.

腕踝针属无痛浅刺法，对神经痛镇痛效果良好，而神经痛发生发展与脊髓中枢敏化密切相关（表现为脊髓背角神经元异常兴奋和胶质细胞活化、神经炎症发生），那么腕踝针可能通过降低脊髓中枢敏化，以发挥镇痛作用，为本项目的科学假说，并拟开展如下研究：（1）建立慢性神经痛大鼠模型，痛行为学评价腕踝针的镇痛效应；基于脊髓fMRI及PET-CT成像、分子生物学等技术，检测脊髓背角神经元活动及葡萄糖代谢，分析腕踝针应用时脊髓神经元异常兴奋及相关递质（谷氨酸、5-HT、β-EP、NMDA受体）的变化情况。（2）免疫组化和分子生物学等方法，检测脊髓胶质细胞活化及炎症细胞因子等指标变化，分析腕踝针应用时脊髓胶质细胞活化和神经炎症的变化情况。（3）脊髓鞘内注射NMDA、5-HT及β-EP受体拮抗剂，观察其对腕踝针镇痛效应及脊髓神经元兴奋性变化的影响。研究结果将揭示腕踝针镇痛的脊髓中枢机制，为腕踝针临床推广应用提供重要依据。

腕踝针属无痛浅刺法，对神经痛镇痛效果良好，而神经痛发生发展与脊髓、脑中枢敏化密切相关（如脊髓背角神经元异常兴奋和胶质细胞活化、神经炎症发生），那么腕踝针可能通过降低中枢敏化，以发挥镇痛作用，为本项目的科学假说。主要研究内容包括：（1）建立慢性神经痛大鼠模型，痛行为学评价腕踝针的镇痛效应；基于脊髓fMRI及PET-CT成像、分子生物学等技术，检测脊髓背角神经元活动及葡萄糖代谢，分析腕踝针应用时脊髓神经元异常兴奋及相关递质（谷氨酸、5-HT、β-EP、NMDA受体）的变化情况。（2）免疫组化和分子生物学等方法，检测脊髓胶质细胞活化及炎症细胞因子等指标变化，分析腕踝针应用时脊髓胶质细胞活化和神经炎症的变化情况。（3）脊髓鞘内注射NMDA、5-HT及β-EP受体拮抗剂，观察其对腕踝针镇痛效应及脊髓神经元兴奋性变化的影响。研究结果表明：（1）腕踝针可显著降低神经痛大鼠机械痛、热痛敏化，提高痛阈值。（2）fMRI及PET-CT成像结果显示，神经痛发生过程中，脊髓背角谷氨酸含量及NMDAR1磷酸化蛋白表达显著增加，海马区及内侧前额叶葡萄糖代谢显著减低、背侧丘脑与岛叶功能连接显著增强，背侧丘脑NAA神经递质显著降低。腕踝针可降低脊髓背角谷氨酸及其受体NR1含量，提高海马、内侧前额叶等疼痛矩阵脑区葡萄糖代谢。（3）免疫组化、ELISA等方法检测提示，腕踝针通过抑制脑干中缝大核5-HT合成，降低脊髓背角5-HT释放，降低5-HT受体的表达。（4）腕踝针可提高脊髓背角β-EP和IL-10含量，发挥镇痛作用。（5）腕踝针可抑制脊髓背角小胶质细胞、星形胶质细胞活性，降低炎症因子释放，发挥抗炎镇痛作用。