电针通过下调rACC谷氨酸能神经元活性缓解慢性炎性痛大鼠焦虑样行为*

Electroacupuncture alleviated the chronic inflammatory pain-induced anxiety-like behaviors by decreasing the activity of glutamate neurons in rostral anterior cingulate cortex

摘要:

目的：探讨吻侧前扣带皮层(rostral anterior cingulate cortex, rACC)谷氨酸能神经元活性是否与慢性炎性痛诱发焦虑样行为相关,明确电针是否通过调控rACC谷氨酸能神经元活性起到抗焦虑样行为作用。方法：1.足底皮下注射完全弗氏佐剂(complete Freund’s adjuvant, CFA)建立大鼠慢性炎性痛模型；2.通过注射化学遗传病毒调控rACC谷氨酸能神经元活性,并使用动态足底触觉仪和旷场实验(open field test, OFT)分别检测其机械性痛阈(paw withdrawl thresholds, PWTs)和焦虑样行为改变；3.观察调控rACC谷氨酸能神经元是否对电针(electroacupuncture, EA)足三里、三阴交穴的抗炎性痛和抗焦虑样行为作用产生影响。结果：1.特异性激活生理状态大鼠rACC谷氨酸能神经元可以诱发焦虑样行为,但不影响其痛阈; 2.特异性抑制rACC谷氨酸能神经元缓解CFA模型大鼠的焦虑样行为,但不影响其痛阈; 3.电针对CFA大鼠焦虑样行为的作用被特异性激活rACC谷氨酸能神经元逆转,但电针镇痛作用未受影响。结论：电针通过下调rACC谷氨酸能神经元活性缓解慢性炎性痛大鼠的焦虑样行为。

Abstract:

Objective: To explore the mechanism of glutamatergic neurons in rostral anterior cingulate cortex (rACC) in regulating hyperalgesia and pain-induced anxiety-like behavior in chronic inflammatory pain model rats, and the effect of electroacupuncture intervention. Methods: 1. The chronic inflammatory pain model was replicated by injecting 0.1ml emulsified CFA into the left hind plantar. 2. Neuronal activity was regulated by injection of adeno-associated virus, paw withdraw thresholds (PWTs) and anxiety-like behaviors were measured by dynamic plantar tactile instrument and OFT respectively. 3. To investigate whether the activation of rACC glutamate neurons affects the electroacupuncture (EA) intervention on pain and pain related anxiety-like behaviors by stimulation the acupoint of “Zusanli” (ST36) and “Sanyinjiao” (SP6) . Results: 1. Specific activation of glutaminergic neurons in the rACC induced anxiety-like behaviors in normal rats, but didn’t affect the PWTs. 2. Specifically inhibiting the glutamatergic neurons in the rACC alleviated the pain-induced anxiety-like behaviors in CFA model rats, but did not affect the PWTs. 3. The antianxietic effect of EA was reversed by specifically activating glutamatergic neurons in the rACC, but the PWTs had no changes. Conclusion: Electroacupuncture alleviated the chronic inflammatory pain-induced anxiety-like behaviors by decreasing the activity of glutamate neurons in the rostral anterior cingulate cortex.