电针调节纹状体中型棘突神经元异常电活动在改善帕金森病运动症状中的机制研究

Electro-acupuncture (EA) stimulation alleviated motor symptoms of parkinsonian animal models and patients, but the mechanisms are unclear. Recent studies suggested abnormal electrophysiological characters of striatum trigged the motor dysfunction on PD state. Our original results indicated EA activated medium spiny neuron (MSN) and regulated abnormal local field potential in striatum. MSN in striatum was divided into two groups. One expressed dopamine receptor I, called D1-MSN. The other expressed dopamine receptor II, called D2-MSN. Which one is activated by EA, and whether MSN is contributed to the attenuation of abnormal striatum local field potential and motor symptoms by EA need to be further investigated. Therefore, in vivo calcium imaging was used to observe the activity of either D1-MSN or D2-MSN after a long term EA therapy in PD mice model. Then the optogenetics combined with in vivo recording technology was used to discriminate D1-MSN and D2-MSN recording. The electrophysiological characters of either D1-MSN or D2-MSN and local field potential of striatum were recorded at the same time of EA stimulation in PD mice model. Finally, we will use optogenetics to selected inhibit either D1-MSN or D2-MSN, and then find out the cause effect relationship between MSNs and abnormal striatum local field potential or motor symptoms in PD mice model. This study will provide more scientific explanations of EA stimulation on PD.

电针有效改善帕金森病（PD）运动症状但机制不明。研究表明纹状体异常放电是PD运动症状的首要环节之一。我们原创性前期研究提示长期电针调节纹状体中型棘突神经元（MSN）及纹状体异常场电位。但电针调节MSN的种类（D1-MSN或/和D2-MSN）及通过何种MSN改善纹状体异常放电进而缓解PD运动症状仍需进一步证实。因此本课题利用D1-Cre/D2-Cre转基因小鼠结合在体清醒钙成像方法动态观察长期电针对PD小鼠D1-MSN/D2-MSN电活动改变，明确电针对两种MSN的长期调节作用；利用光遗传学结合在体电生理技术在体区分D1-MSN/D2-MSN，明确电针刺激同时对PD小鼠MSN电活动及纹状体异常场电位的即时调节作用；最后利用光遗传学方法在电针刺激同时特异性阻断D1-MSN/D2-MSN，明确MSN的即时效应与长期电针对纹状体异常电活动及运动症状改善的因果关系，有助于科学解释针灸防治PD的机理.

电针可有效改善帕金森病（PD）的运动症状，但机制研究一直处于探索当中。研究表明纹状体异常放电引起的基底节环路失衡是PD产生运动症状的首要环节。因此本研究以纹状体中型棘突神经元（MSN）为切入点，首先揭示了长期电针在改善PD小鼠模型运动症状的同时还调节了纹状体MSN结构和功能可塑性。其次利用转基因动物结合在体神经元钙成像技术，发现长期电针刺激可调节D1-MSN和D2-MSN活动，之后细化PD小鼠运动症状，发现长期电针调节D1-MSN的同时可改善PD小鼠的运动启动障碍。进一步利用在体电生理及钙成像技术发现除了长期电针刺激，急性电针刺激就可引起D1-MSN活动改变，且随着刺激强度增加而增强，但非穴位电针刺激或电针刺激麻醉小鼠均不能引起D1-MSN活动改变。最后利用光遗传学技术在电针刺激PD小鼠的同时抑制纹状体D1-MSN的活动，发现长期电针却不能改善PD小鼠运动速度以及运动启动障碍，表明电针可能通过增强D1-MSN的活动改善PD小鼠运动症状。因此本研究明确了D1-MSN在电针调节PD运动症状的关键作用，并且发现电针主要是通过调节D1-MSN改善PD小鼠的运动启动障碍。为阐明电针改善PD运动症状提供了直接的实验基础和理论依据，有助于科学解释针灸防治PD的机理。