Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Zhen Ci Yan Jiu. 2024 May 25;49(5):448-455. doi: 10.13702/j.1000-0607.20231020.
To observe the effect of electroacupuncture (EA) at different intensities on nociceptive discharges of wide dynamic range (WDR) neurons in the spinal dorsal horns (DHs) of rats, so as to explore its regulatory characteristics on nociceptive signals at the spinal level.
A total of 25 male SD rats were used in the present study. A microelectrode array was used to record the discharge activity of WDR neurons in the lumbar spinal DHs of normal rats. After finding the WDR neuron, electrical stimulation (pulse width of 2 ms) was administered to the plantar receptive field (RF) for determining its response component of discharges according to the latency of action potential generation (Aβ ［0 to 20 ms］, Aδ ［20 to 90 ms］, C ［90 to 500 ms］ and post-discharge ［500 to 800 ms］). High-intensity electrical stimulation was continuously applied to the RF at the paw's plantar surface to induce DHs neuronal windup response. Subsequently, EA stimulation at different intensities (1 mA and 2 mA) was applied to the left "Zusanli"(ST36) at a frequency of 2 Hz/15 Hz for 10 min. The induction of WDR neuronal windup was then repeated under the same conditions. The quantity of nociceptive discharge components and the windup response of WDR neurons before and after EA stimulations at different intensities were compared.
Compared to pre-EA, both EA and EA significantly reduced the number of Aδ and C component discharges of WDR neurons during stimulation, as well as post-discharge (<0.01, <0.001). The inhibitory rate of C component by EA was significantly higher than that by EA (<0.05). Meanwhile, both EA and EA attenuated the windup response of WDR neurons (<0.05, <0.01), and the effect of EA was stronger than that of EA (<0.05). Further analysis showed that when EA and EA respectively applied to both non-receptive field (non-RF) and RF, a significant reduction in the number of Aδ component, C component and post-discharge was observed (<0.05, <0.01). EA at the non-RF and RF demonstrated a significant inhibitory effect on the windup response of WDR neurons (<0.01, <0.05), but EA only at the non-RF showed a significant inhibitory effect on the windup response (<0.01).
EA can suppress nociceptive discharges of spinal DHs WDR neurons in rats. The inhibitory impact of EA is strongly correlated with the location and intensity of EA stimulation, and EA has a stronger inhibitory effect than EA.
观察不同强度电针对大鼠脊髓背角（DH）宽动态范围（WDR）神经元伤害性放电的影响，探讨其对脊髓水平伤害性信号的调节特征。
本研究共使用 25 只雄性 SD 大鼠。使用微电极阵列记录正常大鼠脊髓 DH 中 WDR 神经元的放电活动。在找到 WDR 神经元后，根据动作电位产生的潜伏期（Aβ[0-20ms]、Aδ[20-90ms]、C[90-500ms]和后放电[500-800ms]）给予足底感觉野（RF）电刺激（脉冲宽度 2ms），以确定其放电反应成分。在足底表面持续给予高强度电刺激 RF，以诱导 DH 神经元的 windup 反应。随后，在相同条件下，分别以 1mA 和 2mA 强度施加左“足三里”（ST36）的 EA 刺激，频率为 2Hz/15Hz，持续 10min。在相同条件下再次重复 WDR 神经元 windup 的诱导。比较不同强度 EA 刺激前后 WDR 神经元伤害性放电成分的数量和 windup 反应。
与 EA 刺激前相比，EA 和 EA 刺激均显著减少了 WDR 神经元在刺激过程中 Aδ 和 C 成分的放电次数，以及后放电（<0.01，<0.001）。EA 对 C 成分的抑制率明显高于 EA（<0.05）。同时，EA 和 EA 均减弱了 WDR 神经元的 windup 反应（<0.05，<0.01），且 EA 的作用强于 EA（<0.05）。进一步分析表明，当 EA 和 EA 分别应用于非感受野（non-RF）和 RF 时，Aδ 成分、C 成分和后放电的数量均显著减少（<0.05，<0.01）。EA 刺激 non-RF 和 RF 均对 WDR 神经元的 windup 反应具有显著抑制作用（<0.01，<0.05），但仅 EA 刺激 non-RF 对 windup 反应具有显著抑制作用（<0.01）。
EA 可抑制大鼠脊髓 DHs WDR 神经元的伤害性放电。EA 的抑制作用与 EA 刺激的位置和强度密切相关，且 EA 的抑制作用强于 EA。
