正常及MPTP帕金森病模型小鼠苍白球orexin-A的电生理效应及其受体机制

发布时间：2018-04-24 18:57

本文选题：苍白球 + orexin-A　；参考：《青岛大学》2017年硕士论文

【摘要】：Orexins是下丘脑神经肽家族中的一员,在中枢神经系统的运动调节功能中起重要作用。已有文献证明,帕金森病患者和动物模型脑内orexin水平明显降低。苍白球是基底神经节间接通路的重要核团,在机体运动协调等方面发挥重要作用,其功能异常与许多运动功能障碍疾病相关。形态学研究表明,苍白球接受orexin纤维投射并表达orexin-1受体(OX1R)。目的:探究在正常及MPTP(1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine,MPTP)帕金森病模型小鼠,苍白球orexin-A的电生理效应及其受体机制。方法:本实验采用多管微电极在体细胞外电生理记录、MPTP帕金森病小鼠模型制备以及免疫组织化学染色等实验方法。结果:1.在体细胞外电生理实验中记录的59个正常小鼠苍白球神经元,平均放电频率为8.43±0.55 Hz。苍白球神经元呈现三种放电模式,其中29个(49.15%)呈规则放电,22个(37.29%)呈不规则放电,8个(13.56%)呈簇状放电。2.在正常小鼠记录到38个苍白球神经元,有21个神经元在微量压力注射orexin-A(0.01m M)后自发放电频率由7.77±0.94 Hz升高到11.10±1.23 Hz,平均升高51.26±6.36%(t=-7.20,P=0.000)。经过对放电模式CV值和FF值分析,orexin-A使CV值增加(加药前:0.50±0.09;加药后:0.63±0.09),差异有统计学意义(t=-2.48,P=0.02),对FF值无明显影响(加药前:0.12±0.04;加药后:0.11±0.04,t=0.47,P=0.65)。3.正常小鼠苍白球微量注射OX1R阻断剂SB-334867(0.01m M),在记录到的33个神经元中,有23个自发放电频率由8.71±0.95 Hz降低至3.50±0.63 Hz,平均降低61.77±5.42%,加药前与加药后比较,差异有显著统计学意义(t=7.69,P=0.000)。SB-334867使CV值增加(加药前:0.89±0.12;加药后:1.17±0.12;t=-3.32,P=0.003),并使FF值增加(加药前:0.21±0.07;加药后:0.70±0.16;t=-3.52,P=0.002),差异均有统计学意义。该结果提示苍白球orexin-A递质系统能够改变苍白球神经元放电模式。4.正常小鼠记录到7个苍白球神经元,联合微量注射0.01m M SB-334867和0.01m M orexin-A,使苍白球神经元放电频率自4.66±1.28Hz升高至5.12±1.34 Hz,平均升高13.16±3.19%。待完全恢复后,在同一神经元中再单独给予0.01m M orexin-A,苍白球神经元放电频率自5.15±1.16Hz升高至7.40±1.68 Hz,平均升高46.43±7.22%,与之前联合给予SB-334867和orexin-A组比较差异有统计学意义(z=-2.49,P=0.011)。5.在MPTP帕金森病模型小鼠记录到的33个苍白球神经元,自发放电频率平均为7.64±0.96 Hz,与正常小鼠相比无明显差异(t=0.42,P=0.68)。放电模式分析显示12个(36.36%)神经元呈规则放电,16个(48.49%)神经元呈不规则放电,5个(15.15%)神经元呈簇状放电。MPTP帕金森病模型小鼠苍白球神经元的规则放电百分比较正常小鼠有所减少,而不规则放电以及簇状放电的百分比有所增加,但χ2检验结果显示差异无显著性(χ2=1.42,d.f.=2,P0.05)。6.在MPTP帕金森病模型小鼠,苍白球微量压力注射0.01m M orexin-A可以使记录到的23个神经元中的14个神经元产生兴奋效应,使其自发放电频率由6.14±1.17 Hz升高到10.40±1.82 Hz,平均升高83.78±16.82%(t=-5.20,P=0.000)。对放电模式CV值(加药前:0.49±0.09;加药后:0.60±0.11;t=-1.40,P=0.19)和FF值(加药前:0.16±0.08;加药后:0.13±0.07;t=0.22,P=0.83)分析,差异无统计学意义。有2个苍白球神经元在微量压力注射0.01m M orexin-A后自发放电频率由5.95±2.58 Hz降低到3.12±1.02 Hz,平均降低44.58±6.89%(t=1.81,P=0.32)。7.帕金森病模型小鼠苍白球微量注射OX1R阻断剂SB-334867(0.01m M),在记录到的10个神经元中,有7个自发放电频率由6.71±1.47 Hz降低至2.49±1.09 Hz,平均降低68.84±8.40%,加药前与加药后比较,差异有显著统计学意义(t=5.91,P=0.001)。SB-334867使CV值增加(加药前:0.99±0.12;加药后:1.33±0.12;t=-6.09,P=0.001),并使FF值增加(加药前:0.18±0.04;加药后:0.61±0.11;t=-5.60,P=0.001),差异均有统计学意义。8.Orexin-A对MPTP帕金森病模型小鼠苍白球神经元的兴奋效应较正常小鼠明显增强,差异有统计学意义(z=-2.02,P=0.04);而SB-334867对正常小鼠和MPTP帕金森病模型小鼠苍白球神经元的抑制效应比较,差异无统计学意义(z=-0.19,P=0.85)。9.免疫组织化学染色显示正常和MPTP帕金森病模型小鼠苍白球均可表达OX1R,且表达量相当(P0.05)。两种小鼠下丘脑外侧区的orexin-A的表达量也无显著差异(P0.05)。结论:Orexin-A通过激活OX1R提高正常和MPTP帕金森病模型小鼠苍白球神经元兴奋性,且orexin-A对帕金森病模型小鼠苍白球神经元的兴奋效应较正常小鼠增强。SB-334867能够抑制正常和帕金森病模型小鼠苍白球神经元放电频率,提示内源性orexin主要通过OX1R发挥作用。本实验为苍白球orexin递质系统参与帕金森病发病提供了一定的理论和实验依据。
[Abstract]:Objective : To investigate the electrophysiological effects of orexin - A and orexin - 1 receptor ( OX1R ) in normal and MPTP ( 1 - Methyl - 4 - phenyl - 1,2,3,6 - tetrahydropyridine , MPTP ) Parkinson ' s disease . The results showed that : 1 . In normal and MPTP ( 1 - Methyl - 4 - phenyl - 1,2,3,6 - tetrahydropyridine , MPTP ) Parkinson ' s disease model mice , the frequency of spontaneous discharge was increased from 7.77 卤 0.94 Hz to 11.10 卤 1.23 Hz , with an average increase of 51.26 卤 6.36 % ( t = - 7.20 , P = 0.000 ) . In the 33 neurons recorded , 23 spontaneous discharge frequencies were reduced from 8.71 卤 0.95 Hz to 3.50 卤 0.63 Hz , the mean decrease was 61.77 卤 5.42 % , and the difference was statistically significant ( t = 7.69 , P = 0.000 ) . The results suggested that the neurons of the pallidosphere orexin - A were able to change the discharge pattern of the pallidus . The results suggested that the neurons of the pallidosphere orexin - A were able to change the discharge pattern of the pallidus . The results suggested that the neurons of the pallidosphere orexin - A could change the discharge pattern of the pallidus . The results suggested that the neurons of the pallidosphere orexin - A could change the discharge frequency of the neurons from 4.66 卤 1.28Hz to 5.12 卤 1.68Hz , the average increase was 13.16 卤 3.19 % . The results showed that 12 ( 36.36 % ) neurons showed regular discharge , 16 ( 48.49 % ) neurons were irregular discharges , 5 ( 15.15 % ) neurons were in cluster - like discharge . The percentage of irregular discharges and cluster - like discharges increased significantly in MPTP Parkinson ' s disease model mice , and the results showed no significant difference ( 蠂 ~ 2 = 1.42 , d.f . = 2 , P0.05 ) . The frequency of spontaneous discharge was reduced from 5.95 卤 2.58 Hz to 3.12 卤 1.02 Hz , with an average decrease of 44.58 卤 6.89 % ( t = 1.81 , P = 0.32 ) . The results showed that orexin - A significantly increased the expression of orexin - A in normal and MPTP Parkinson ' s disease model mice .

【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R742.5;R-332

【参考文献】