不同强度电针对大鼠脊髓背角广动力神经元伤害性放电的抑制作用OA北大核心CSTPCDMEDLINE

Objective 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.Methods 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.Results Compared to pre-EA,both EA1 mA and EA2 mA significantly reduced the number of Aδ and C component discharges of WDR neurons during stimulation,as well as post-discharge(P<0.01,P<0.001).The inhibitory rate of C component by EA2 mA was significantly higher than that by EA1 mA(P<0.05).Meanwhile,both EA1 mA and EA2 mA attenuated the windup response of WDR neurons(P<0.05,P<0.01),and the effect of EA2 mA was stronger than that of EA1 mA(P<0.05).Further analysis showed that when EA1 mA and EA2 mA 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(P<0.05,P<0.01).EA2 mA at the non-RF and RF demonstrated a significant inhibitory effect on the windup response of WDR neurons(P<0.01,P<0.05),but EA1 mA only at the non-RF showed a significant inhibitory effect on the windup response(P<0.01).Conclusion 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 EA2 mA has a stronger inhibitory effect than EA1 mA.