不同针刺方法对神经病理性镜像痛大鼠负性情绪和前扣带皮层小胶质细胞增殖和形态的影响

Effects of different acupuncture methods on negative emotions and microglial proliferation and morphology of anterior cingulate cortex in rats with mirror-image neuropathic pain

目的:观察不同针刺方法对神经病理性镜像痛大鼠前扣带皮层(ACC)小胶质细胞增殖和形态的影响,探讨不同针刺方法对镜像痛大鼠负性情绪的干预机制。方法:40只雄性SD大鼠随机分为空白(A)组、模型(B)组、2/100Hz电针(C)组、弱刺激手针(D)组。后3组采用L5脊神经结扎(SNL)法制备神经病理性痛镜像痛模型。于SNL前,SNL后3、7、12d时检测双侧后足机械痛阈。SNL后12d,采用旷场试验观察大鼠负性情绪行为,免疫荧光法计算各组前扣带皮层OX-42阳性细胞数量并观察形态变化。结果:SNL后12d,与A组比较,B、D组双侧痛阈明显下降(P<0.05),B、C组大鼠负性情绪行为明显增加(P<0.05),且伴随ACC区域OX-42阳性细胞显著增加(P<0.05),形状呈激活状态;与B组比较,C组双侧痛阈明显升高(P<0.05),D组负性情绪行为明显减缓(P<0.05),且伴随ACC区域OX-42阳性细胞显著减少(P<0.05),形状呈静息状态。结论:弱刺激手针缓解神经病理性镜像痛负性情绪的机制可能与抑制ACC小胶质细胞增殖活化相关。

Objective： To observe the effect of different acupuncture methods on negative emotions and microglial proliferation and morphology in anterior cingulate cortex（ACC） in rats with mirror-image neuropathic pain, so as to explore its mechanisms underlying pain-induced negative emotions. Methods： Forty male SD rats were equally and randomly divided into control（group A）, spinal nerve ligation（SNL） model（group B）, 2/100 Hz electroacupuncture（group C）, mild manual acupuncture stimulation（group D） groups. Neuropathic pain model was established by ligature of the spinal nerve（L5）. Bilateral paw withdrawal thresholds（PWTs） were measured before SNL and 3, 7, and 12 days after SNL. Twelve days after the SNL, open field test was used to identify the negative emotions and immunofluorescence method was applied to observe the number and morphologic changes of OX-42 positive cells in the ACC. Results： In comparison with group A, the bilateral PWTs were significantly decreased in group B and D on the 12 th day（P〈0.05）. Compared with group B, the bilateral PWTs were significantly increased in group C on the 12 th day（P〈0.05）. The negative emotions-like behavior in group B increased compared with group A, and the same with group C on the 12 th day（P〈0.05）, whereas the mild manual acupuncture intervention decreased the negative emotions with group B（P〈0.05）. OX-42 positive cells in group B and C have an overexpression and been in an active state in the ACC, while group D have a lower level than group B（P〈0.05） and been in a resting state. Conclusion： Mild manual acupuncture stimulation can alleviate mirror-image pain induced negative emotions in SNL rats, which is closely related to its effect in downregulating microglial proliferation and activation in the ACC.