Zuo Yan, Liu Yong-Bin, Yuan Zi-Yan, DU Rui-Bing, Wu Yu-Wei, Xue Si-Meng, Diao Zhi-Jun, Qiao Hai-Fa
College of Acupuncture-moxibustion and Tuina of Shaanxi University of Chinese Medicine.
Shaanxi Key Laboratory of Acupuncture and Medicine.
Zhen Ci Yan Jiu. 2024 Nov 25;49(11):1121-1128. doi: 10.13702/j.1000-0607.20230738.
To elucidate the relationship between the auricular point stimulation and the activity of glutamatergic neurons in the anterior cingulate cortex (ACC) from the perspective of intrinsic excitability plasticity of neurons in mice with posttraumatic stress disorder (PTSD), so as to explore the underlying mechanisms of acupuncture at auricular points in improving emotional diseases induced by PTSD.
C57BL/6J male mice were randomly divided into control, PTSD model, sham electroacupuncture (EA), and EA groups, with 5 mice in each group. The glutamatergic neurons were labelled by injection of AAV2/9-CaMKⅡα-EGFP viral fluid into the bilateral ACC. Fourteen days after the injection, the PTSD model was established by single prolonged stress (restraint stress, forced swimming, ether exposure) and plantar electrical shock. EA (2 Hz/15 Hz, 1 mA) was applied to bilateral "Xin" points and the center of auriculae of auricular concha area for 30 min, once daily for 7 days. Mice of the sham EA group were anesthetized for 30 min per day for 7 days, but no EA treatments were given. The anxiety-like behavior of mice was evaluated by open field (OF) and elevated plus maze (EPM) tests after 2 weeks of modeling. The whole-cell patch-clamp method was used to record the intrinsic excitability level of ACC glutamatergic neurons.
Compared with the control group, the dwell time and locomotor distance in the central area of the OF, the dwell time and entry times percentage in the open arms of the EPM in the model group were significantly reduced (<0.001, <0.01). At the same time, the intrinsic excitability of ACC glutamatergic neurons in model mice was suppressed, presenting as enhanced rheobase currents (<0.01) and decreased spike number (<0.05, <0.01, <0.001). Compared with the model group, the dwell time and locomotor distance in the central area of the OF, the dwell time and entry times percentage in the open arms of the elevated plus maze were significantly increased (<0.001, <0.01), and the intrinsic excitability of ACC glutamatergic neurons was significantly improved, presenting as reduced rheobase currents (<0.05) and an increased spike number (<0.05) in the EA group. Compared with the sham EA group, the dwell time and locomotor distance in the central area of the OF, the dwell time and entry times percentage in the open arms of the EPM were significantly increased (<0.001, <0.01) in the EA group, and the intrinsic excitability of ACC glutamatergic neurons was significantly improved, presenting as reduced rheobase currents (<0.01) and an increased spike number (<0.05).
EA of auricular points can effectively alleviate the anxiety-like behavior of PTSD mice and increase the intrinsic excitability level of glutamatergic neurons in ACC, which may be one of the neural mechanisms of auricular point stimulation in the treatment of emotional diseases.
从创伤后应激障碍（PTSD）小鼠神经元内在兴奋性可塑性的角度，阐明耳穴刺激与前扣带回皮质（ACC）中谷氨酸能神经元活动之间的关系，以探讨耳穴针刺改善PTSD所致情绪疾病的潜在机制。
将C57BL/6J雄性小鼠随机分为对照组、PTSD模型组、假电针（EA）组和EA组，每组5只。通过向双侧ACC注射AAV2/9-CaMKⅡα-EGFP病毒液标记谷氨酸能神经元。注射后14天，采用单次延长应激（束缚应激、强迫游泳、乙醚暴露）和足底电击建立PTSD模型。将EA（2Hz/15Hz，1mA）施加于双侧“心”穴及耳甲腔区域耳郭中央，持续30分钟，每天1次，共7天。假电针组小鼠每天麻醉30分钟，共7天，但不给予电针治疗。建模2周后，通过旷场（OF）和高架十字迷宫（EPM）试验评估小鼠的焦虑样行为。采用全细胞膜片钳方法记录ACC谷氨酸能神经元的内在兴奋性水平。
与对照组相比，模型组小鼠在OF中央区域的停留时间和运动距离、在EPM开放臂的停留时间和进入次数百分比均显著降低（<0.001，<0.01）。同时，模型小鼠ACC谷氨酸能神经元的内在兴奋性受到抑制，表现为阈电流增强（<0.01）和顺次发放次数减少（<0.05，<0.01，<0.001）。与模型组相比，EA组小鼠在OF中央区域的停留时间和运动距离、在高架十字迷宫开放臂的停留时间和进入次数百分比均显著增加（<0.001，<0.01），ACC谷氨酸能神经元的内在兴奋性显著改善，表现为阈电流降低（<0.05）和顺次发放次数增加（<0.05）。与假电针组相比，EA组小鼠在OF中央区域的停留时间和运动距离、在EPM开放臂的停留时间和进入次数百分比均显著增加（<0.001，<0.01），ACC谷氨酸能神经元的内在兴奋性显著改善，表现为阈电流降低（<0.01）和顺次发放次数增加（<0.05）。
耳穴电针可有效缓解PTSD小鼠的焦虑样行为，提高ACC中谷氨酸能神经元的内在兴奋性水平，这可能是耳穴刺激治疗情绪疾病的神经机制之一。
