Study on intervention mechanism of acupuncture for neuron abnormal neural coding in visual cortex area 17 of monocular deprivation rats

Abstract

Objective

To investigate the electrophysiological mechanism of acupuncture for the visual cortex plasticity during the sensitive period.

Methods

Fifty 2-week-old Wistar rats were randomly divided into a blank control group, a model group, an early-stage acupuncture group, a middle-stage acupuncture group and a late-stage acupuncture group, 10 rats in each group. Monocular deprivation amblyopia models were prepared in rats except those in the blank control group by unilateral eyelid suture. After successful modeling, no treatment was applied to the rats in the model group. Rats in each acupuncture group were treated with acupuncture at bilateral Jingming (BL 1), Cuanzhu (BL 2), Fengchi (GB 20) and Guangming (GB 37), started from the 3rd day, 12th day or 21st day after modeling separately, once a day, for a total of 9 d treatment. The neuronal discharge frequency and action potential inter-spike interval (ISI) in the rat visual cortex area 17 of each group were measured by multi-channel microelectrode array nerve signal technique.

Results

The discharge number of neurons in the visual cortex of the model group was significantly lower than that in the blank control group (P<0.05). After treatment, the discharge numbers in the early-stage acupuncture group and the middle-stage acupuncture group were significantly higher than that in the model group (P<0.05). There was no significant difference in the discharge numbers between the late-stage acupuncture group and the model group (P>0.05). The discharge number in the middle-stage acupuncture group was lower than that in the early-stage acupuncture group (P<0.05), and the discharge number of the late-stage acupuncture group was lower than that in the middle-stage acupuncture group (P<0.05). The ISI sequences of the visual cortex neurons were mainly distributed under 0.3 s in the blank control group, under 15 s in the model group, under 1 s in the early-stage acupuncture group, under 4 s in the middle-stage acupuncture group, and under 10 s in the late-stage acupuncture group, divergent in each group.

Conclusion

The neuronal coding appears abnormality in the visual cortex area 17 of monocular deprivation rats, indicating that there is a plasticity change in the visual cortex neurons during the sensitive period. Acupuncture has a significant effect on the abnormal neural coding. The therapeutic efficacy is closely related to the stage to start the treatment. Early stage treatment in the sensitive period is the key to achieving the good efficacy.

摘要

目的

探讨敏感期内针刺干预视皮层可塑性的电生理机制。

方法

将50 只2 周龄的Wistar 大鼠随机分 为空白组、模型组、早期针刺组、中期针刺组和末期针刺组, 每组10 只。正常组不予任何处理, 模型组和各针 刺组采用单侧眼睑缝合的方法复制单眼剥夺弱视模型。造模成功后模型组不予任何治疗, 各针刺组选取双侧睛 明、攒竹、风池和光明分别在造模后第3 d、12 d 和21 d 开始针刺治疗, 每日1 次, 共治疗9 d。采用在体多通道 微电极阵列神经信号技术检测各组大鼠视皮层17 区神经元放电频率及动作电位峰-峰间期(ISI)。

结果

模型组大 鼠视皮层神经元放电次数较空白组显著减少(P<0.05); 治疗后早、中期针刺组放电次数较模型组明显增加 (P<0.05), 末期针刺组放电次数与模型组差异无统计学意义(P>0.05); 中期针刺组放电次数低于早期针刺组 (P<0.05), 末期针刺组放电次数低于中期针刺组(P<0.05)。空白组大鼠视皮层神经元ISI 序列集中分布在0.3 s 以 下, 模型组在15 s 以下, 早期针刺组在1 s 以下, 中期针刺组在4 s 以下, 末期针刺组在10 s 以下, 各组均呈发散 状。

结论

单眼剥夺后大鼠视皮层17 区神经元出现神经编码异常改变, 表明敏感期内视皮层神经元存在可塑性 变化; 而针刺对异常的神经编码有明显的调节作用, 且针刺疗效与治疗时机密切相关, 敏感期内早期治疗是取得 疗效的关键。