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1、生理学报ActaPhysiologicaSinica,August25,2011,63(4):311–318311http://www.actaps.com.cn研究论文低频电刺激大鼠脚桥核对丘脑腹外侧核神经元自发放电的影响及其机制1211112,*刘焕,林宇涵,程九华,蔡越,於进文,马进,高东明12第四军医大学航空航天医学教育部重点实验室,航空航天生理学教研室,西安710032;辽宁医学院生理学教研室,锦州121001摘要:本文旨在观察低频电刺激脚桥核(pedunculopontinenucleus,
2、PPN)对帕金森病(Parkinson’sdisease,PD)模型大鼠丘脑腹外侧核(ventrolateralthalamicnucleus,VL)神经元自发放电活动的影响,以探讨低频电刺激PPN改善PD症状的作用机制。通过纹状体内注射6-羟多巴胺制备PD大鼠模型。采用在体细胞外记录、电刺激及微电泳方法,观察低频电刺激PPN、微电泳乙酰胆碱(acetylcholine,ACh)及其M型受体阻断剂阿托品(atropine,ATR)、γ-氨基丁酸(γ-aminobutyricacid,GABA)及其A型受
3、体阻断剂荷包牡丹碱(bicuculline,BIC)对大鼠VL神经元放电频率的影响。结果显示,低频电刺激PPN可使正常大鼠和PD大鼠VL神经元自发放电频率增加。微电泳ACh对VL神经元具有兴奋和抑制两种作用,而微电泳ATR则主要抑制VL神经元,即使对被ACh抑制的神经元也产生抑制作用。微电泳GABA抑制VL神经元,而微电泳BIC则兴奋VL神经元。另外,在微电泳ACh的过程中微电泳GABA,被ACh兴奋或抑制的VL神经元放电频率明显降低。在ATR抑制作用的基础上低频电刺激PPN则不能使VL神经元放电频率增
4、加。以上结果提示,胆碱能和GABA能传入纤维可能会聚于同一VL神经元,并对其具有紧张性作用。低频电刺激PPN可能使该核团投射至VL的胆碱能纤维释放ACh增加,从而通过突触前负反馈调节抑制投射至基底节输出核VL的GABA能通路,释放丘脑–皮层投射,使相应运动皮层活动提高而改善PD症状。关键词:帕金森病;脚桥核;丘脑腹外侧核;微电泳;低频电刺激中图分类号:R338.8Effectsandmechanismoflowfrequencystimulationofpedunculopontinenucleuson
5、spontaneousdischargesofventrolateralthalamicnucleusinratsLIUHuan1,LINYu-Han2,CHENGJiu-Hua1,CAIYue1,YUJin-Wen1,MAJin1,GAODong-Ming2,*1KeyLaboratoryofAerospaceMedicine,MinistryofEducation;DepartmentofAerospacePhysiology,theFourthMilitaryMedicalUniversity,X
6、i’an710032,China;2DepartmentofPhysiology,LiaoningMedicalCollege,Jinzhou121001,ChinaAbstract:Parkinson’sdiseaseisaprogressiveneurodegenerativedisordercharacterizedclinicallybyrigidity,akinesia,restingtremorandposturalinstability.Ithasrecentlybeensuggested
7、thatlowfrequencystimulationofthepedunculopontinenucleus(PPN)hasaroleinthetherapyforParkinsonism,particularlyingaitdisorderandposturalinstability.However,thereislimitedinformationaboutthemechanismoflowfrequencystimulationofthePPNonParkinson’sdisease.Thepr
8、esentstudywastoinvestigatetheeffectandmechanismoflowfrequencystimulationofthePPNonthefiringrateoftheventrolateralthalamicnucleus(VL)inaratmodelwithunilateral6-hydroxydopaminelesioningofthesubstantianigraparscompacta.Invivo