高频电针刺激对帕金森病模型大鼠脑组织中γ-氨基丁酸含量的调节作用

High-frequency electro-acupuncture stimulation modulates intracerebral γ-aminobutyric acid content in rat model of Parkinson’s disease

本研究采用高效液相色谱-电化学法(high pressure/performance liquid chromatography-electrochemical detection,HPLC-ECD)观察电针刺激对帕金森病模型大鼠皮层、纹状体、腹侧中脑和小脑组织中神经递质含量的影响,以探讨电针减轻帕金森病行为症状的可能机制。在Sprague Dawley大鼠内侧前脑束(medial forebrain bundle,MFB)注射6-羟基多巴胺(6-hydroxydop-amine,6-OHDA),建立右侧损伤帕金森病大鼠模型,并将帕金森病大鼠随机分为模型组和100Hz电针治疗组(n=10),后者接受4个疗程(6天为一疗程)的头部百会穴(GV-20)及背部大椎穴(GV-14)电针刺激。另随机选取10只大鼠在MFB仅注射生理盐水(NS)作为假手术组。行为学测试观察电针治疗对阿扑吗啡诱导的大鼠异常旋转行为的影响,HPLC-ECD检测脑组织中γ-氨基丁酸(γ-aminobutyric acid,GABA)含量变化。结果显示,模型组大鼠出现了异常旋转行为,表明帕金森病造模成功。与假手术组相比,模型组大鼠皮层和纹状体损伤侧GABA含量显著增加,腹侧中脑的含量显著降低,而小脑中的含量无显著变化。100Hz电针刺激有效改善了模型大鼠的异常旋转行为;与模型组相比,电针组大鼠皮层损伤侧与非损伤侧GABA含量比值显著减少,纹状体和小脑中两侧GABA含量比值显著增加。以上结果提示,高频电针可以改善帕金森病大鼠的行为症状,可能是通过增强小脑-基底神经节-皮层环路对运动中枢的抑制来发挥作用的。

The purpose of the present study is to observe the effect of electro-acupuncture （EA） stimulation on intracerebral neurotransmitters in a rat model of Parkinson’s disease （PD）, and explore the possible mechanism. We used 6-hydroxydopamine （6-OHDA） injection in medial forebrain bundle （MFB） in the right brain of Sprague Dawley （SD） rat to establish the parkinsonian rat model, and randomly divided the PD rats into model and 100 Hz EA stimulation groups （n =10 in each group）. EA stimulation group received 4 courses of EA stimulation on Baihui （GV-20） and Dazhui （GV-14） acupuncture points. Moreover, ten rats were randomly selected as sham operation group, only receiving normal saline （NS） injection in MFB. Then apomorphine （APO）-induced rotational behavior in different groups was recorded, and the contents of γ-aminobutyric acid （GABA） in the brain were analyzed with high pressure/performance liquid chromatography-electrochemical detection （HPLC-ECD）. The results showed that model group exhibited abnormal rotational behavior with APO treatment, suggesting the successful establishment of PD model. Compared with sham operation group, model group showed increased GABA contents in cortex and striatum, as well as decreased GABA content in ventral midbrain, on the lesioned side. EA stimulation could effectively ameliorate the abnormal rotational behavior of PD rat. Compared with the mod- el group, EA stimulation decreased the ratio of GABA content on the lesioned side to that on unlesioned side in the cortex, while increased the ratios in the striatum and cerebellum. However, there was no difference of the ratio in the ventral midbrain among three groups. These results suggest high-frequency EA stimulation significantly improves the abnormal behavior of PD rats, which may exert through enhancing the inhibitory effect of cerebellum-basal ganglia-cortical loop on motor center.