SYNCHRONIZED RHYTHMIC ACTIVITY OF THE PALLIDUM

苍白球的同步节律活动

基本信息

批准号：
6452797
负责人：
Hitoshi Kita
金额：
$ 11.11万
依托单位：
UNIVERSITY OF TENNESSEE HEALTH SCI CTR
依托单位国家：
美国
项目类别：
财政年份：
2001
资助国家：
美国
起止时间：
2001-05-01 至 2002-04-30
项目状态：
已结题

项目摘要

A loss of midbrain dopaminergic cells results in parkinsonism. It has been hypothesized that parkinsonian rigidity and tremor are associated with abnormal, wide spread synchronized, rhythmic firing of the pallidum. The goal of this proposal is to reveal the mechanisms responsible for the synchronized rhythmic activity of the pallidum. Our basic hypothesis is that the synchronized rhythmic activity is generated because dopamine (DA) depletion has altered the intrinsic membrane properties and synaptic inputs of the pallidum. We hypothesize that pallidal neurons have intrinsic mechanisms for membrane oscillation, and that the membrane oscillatory mechanism is controlled by the DAergic innervation from the midbrain and peptidergic innervations from the neostriatum (Str). To test these hypothesis, physiological and pharmacological studies will be performed using a whole cell recording method in slice preparations. Our study will focus on the potassium and calcium currents involved in the membrane oscillations and effects of DNA and striatal peptides on these currents. Calcium imaging will aid in analyzing the distribution of calcium currents along the dendrites. We hypothesize that the wide synchronization of activity seen in the pallidum of parkinsonian subjects is due to changes in synaptic transmission. Evaluation of this hypothesis should begin with physiological and anatomical studies. To reveal the properties of unitary post-synaptic responses of pallidal neurons to striatal, intra-pallidal, and subthalamic stimulation, and to reveal the effects of DA and striatal peptides on the strength and duration of unitary post-synaptic responses, physiological and pharmacological studies will be performed using a whole cells recording method in slice preparations. All neurons record in the slice experiments will be further characterized for parvalbumin immunoreactivity, somato-dendritic morphology, and at the molecular level for ion channels, receptors, and calcium binding proteins using single cell RT-PCR techniques. To reveal the structural bases for the pallidal synchronizations, intracellular staining of striatal, pallidal, and subthalamic neurons will be performed in anesthetized rats, and the axons of stained neurons will then be analyzed, using computer assisted 3-dimensional reconstruction systems, at both the light and electron microscopic levels. The light microscopic analysis will reveal the number and distribution of synaptic boutons of single axons in the pallidum, and the electron microscopic analysis will reveal the ultrastructure of the synapses, the synaptic pattern, and the structure post-synaptic to the synapses.

中脑多巴胺能细胞的丧失会导致帕金森症。它一直假设帕金森病强直和震颤与苍白球异常、广泛同步、有节奏的发射。这该提案的目标是揭示负责的机制苍白球的同步节律活动。我们的基本假设是同步节律活动的产生是因为多巴胺 (DA) 耗尽改变了内在的膜特性和突触苍白球的输入。我们假设苍白球神经元具有内在机制膜振荡，膜振荡机制是由中脑和肽能的DAergic神经支配控制来自新纹状体（Str）的神经支配。为了检验这些假设，生理学和药理学研究将使用整个切片制备中的细胞记录方法。我们的研究将集中于参与膜振荡的钾电流和钙电流 DNA 和纹状体肽对这些电流的影响。钙成像将有助于分析钙电流沿树突。我们假设在帕金森病受试者的苍白球是由于突触的变化引起的传播。对这个假设的评估应该从生理学和解剖学研究。揭示酉的性质苍白球神经元对纹状体、苍白球内、和底丘脑刺激，并揭示 DA 和纹状体的影响肽对单一突触后反应的强度和持续时间的影响，生理学和药理学研究将使用整个切片制备中的细胞记录方法。所有神经元都记录在切片实验将进一步表征小清蛋白免疫反应性、体细胞树突形态和分子水平对于离子通道、受体和钙结合蛋白，使用单一细胞RT-PCR技术。为了揭示苍白球同步的结构基础，纹状体、苍白球和底丘脑神经元的细胞内染色将在麻醉大鼠中进行，染色的神经元的轴突将然后使用计算机辅助 3 维重建进行分析系统，在光和电子显微镜水平上。光显微镜分析将揭示突触的数量和分布苍白球中单个轴突的纽扣，以及电子显微镜分析将揭示突触的超微结构、突触模式，以及突触后的突触结构。