Zhang Ni-Nan, Zhang Yu-Shan, Zhang Zhi-Yun, Jing Xiang-Hong
Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Zhen Ci Yan Jiu. 2025 Aug 25;50(8):880-888. doi: 10.13702/j.1000-0607.20250186.
To observe the differential analgesic effects of electroacupuncture (EA) at different intensities on calcium activity in dorsal root ganglia (DRG) neurons induced by mechanical, thermal, and cold stimuli in a state of muscular inflammatory pain, so as to preliminarily reveal the peripheral integration characteristics of acupuncture analgesia mechanisms.
The inflammatory muscle pain model was established by injection of complete Freund's adjuvant (CFA) into the right tibialis anterior muscle. EA (0.5 mA or 1 mA, 2 Hz) was applied to "Zusanli" (ST36) on the right side for 10 min. Before and after the EA, mice were given body surface stimulation of brush, clamp and different temperature, while simultaneously recording DRG neuron calcium activity during stimulation. The effects of different stimulation methods before and after EA on the change in fluorescence intensity (ΔF/F0) and the percentage of activated DRG neurons were compared.
In the clamp hind paw stimulation, both 0.5 mA and 1 mA EA could reduce the fluorescence intensity of neurons, and the effect of 1 mA was better than that of 0.5 mA (<0.001). Specifically, 0.5 mA EA decreased the percentage of medium and large neurons (<0.05), while 1 mA EA decreased the percentage of small, medium, and large neurons (<0.05, <0.01), and the effect of 1 mA was better than that of 0.5 mA in reducing the percentage of small and medium neurons (<0.01). In the stimulation of clamping tibialis anterior muscle, both EA intensities could reduce the fluorescence intensity of neurons (<0.05, <0.000 1), and the effect of 1 mA was better than that of 0.5 mA (<0.000 1), and 1 mA EA could reduce the percentage of small and medium neurons (<0.05). In the brush stimulation, both EA intensities could reduce the fluorescence intensity of neurons (<0.000 1), and the effect of 1 mA was better than that of 0.5 mA (<0.000 1), and 0.5 mA EA decreased the percentage of medium and large neurons (<0.05), while 1 mA EA decreased the percentage of small, medium and large neurons (<0.05, <0.01). However, in the temperature stimulation (43, 51, 4 ℃), there were no obvious changes in the fluorescence intensity and the percentage of activated neurons in different intensities of EA.
Both 0.5 mA and 1 mA EA intervention at ST36 can inhibit the reactivity of DRG neurons to mechanical stimulation, with higher intensity EA showing more significant effects.
观察电针（EA）不同强度对肌肉炎性疼痛状态下机械、热和冷刺激诱导的背根神经节（DRG）神经元钙活性的差异镇痛作用，以初步揭示针刺镇痛机制的外周整合特征。
通过向右侧胫骨前肌注射完全弗氏佐剂（CFA）建立炎性肌肉疼痛模型。将EA（0.5 mA或1 mA，2 Hz）施加于右侧“足三里”（ST36）10分钟。在电针前后，对小鼠进行刷擦、夹捏和不同温度的体表刺激，同时记录刺激过程中DRG神经元的钙活性。比较电针前后不同刺激方法对荧光强度变化（ΔF/F0）和激活的DRG神经元百分比的影响。
在夹捏后爪刺激中，0.5 mA和1 mA的电针均可降低神经元的荧光强度，1 mA的效果优于0.5 mA（<0.001）。具体而言，0.5 mA电针降低了中大型神经元的百分比（<0.05），而1 mA电针降低了小型、中型和大型神经元的百分比（<0.05，<0.01），且1 mA在降低中小型神经元百分比方面的效果优于0.5 mA（<0.01）。在夹捏胫骨前肌刺激中，两种电针强度均可降低神经元的荧光强度（<0.05，<0.0001），1 mA的效果优于0.5 mA（<0.0001），且1 mA电针可降低中小型神经元的百分比（<0.05）。在刷擦刺激中，两种电针强度均可降低神经元的荧光强度（<0.0001），1 mA的效果优于0.5 mA（<0.0001），0.5 mA电针降低了中大型神经元的百分比（<0.05），而1 mA电针降低了小型、中型和大型神经元的百分比（<0.05，<0.01）。然而，在温度刺激（43、51、4℃）中，不同强度电针的荧光强度和激活神经元百分比均无明显变化。
ST36处0.5 mA和1 mA的电针干预均可抑制DRG神经元对机械刺激的反应性，较高强度的电针效果更显著。
