Consequences of Synucleinopathy and Dopamine Depletion

帕金森病(PD)和帕金森谱系障碍会产生运动和认知功能障碍 减损。我们建议在帕金森病啮齿动物模型中检测每种类型的行为障碍，L-多巴诱发的运动障碍的程序学习和发展的损害，以及可能存在的纹状体神经可塑性。我们将结合我们和我们的中心成员在以下方面拥有丰富经验的多学科方法：使用系统评级量表进行行为观察、在T-迷宫中进行程序性任务培训、用四极管记录慢性神经元集合神经元、分析早期基因表达、微阵列基因分析和激光捕获显微镜(与项目4合作)，以及引入α-突触核蛋白突变(与项目1和中心外合作)。我们已经开展了广泛的初步研究，并基于非常有希望的发现形成了三个功能目标。在目标1中，我们建议测试在T迷宫中进行程序性学习的过程中，背外侧纹状体任务相关神经元活动的可塑性是否会在单侧6-羟基多巴胺(6-OHDA)损伤限于记录部位周围区域的大鼠中异常。在目标2中，我们建议在基准数据中研究α-突触核蛋白过表达对学习相关神经元可塑性的影响。我们将用注射的老鼠 携带突变或正常形式的α-突触核蛋白的病毒载体，以及表达α-突触核蛋白突变的工程化小鼠。在这两个目标中，动物将在获得学习任务期间或之后接受慢性间歇L-多巴治疗，以测试多巴胺替代治疗对学习和神经元活动的影响。在目的3中，我们建议在6-羟基多巴胺损毁的大鼠中检测L-多巴所致的运动障碍。我们将测量纹状体和基质中即刻早期基因的激活情况，并将表达模式与行为障碍联系起来。我们还将进行基因分析 使用激光解剖的纹状体和基质组织来测量与运动障碍相关的下游基因的不同区段分布。这些实验的结果将为帕金森综合征中涉及的两种纹状体可塑性背后的神经机制提供重要的知识：与程序性学习有关的纹状体可塑性，以及导致L-多巴诱导的帕金森病运动障碍及相关运动障碍的神经机制。

Parkinson's disease (PD) and Parkinson's-spectrum disorders produce both motor and cognitive impairments. We propose to examine behavioral disturbance of each type, impairmen t of procedural learning and development of L-dopa induced dyskinesias, and the striatal neural plasticity that may under lie them in rodent models of PD. We will combine multi-disciplinary methods that we and members of our Center have extensive experience with: behavioral observation using systematic rating scales, training on procedural tasks in a T-maze, chronic neuronal ensemble neuronal recording with tetrodes, analysis of immediate early gene expression, microarray gene assays and laser capture microscopy (collaboration With Project 4), and introduction of alpha-synuclein mutations (collaboration with Project 1 and extra-Center collaborations). We have carried out extensive preliminary studies and formed three functional Aims based on highly promising findings, in Aim 1, we propose to test whether plasticity in task-related neuronal activity in the dorsolateral striatum during a procedural learning in a T-maze will be abnormal in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions restricted to the area around the recording sites, in Aim 2, we propose to study the effects of alpha-synuclein overexpression on learning-related neuronal plasticity in the stdatum. We will use rats injected with viral vectors carrying mutant or normal forms of alpha-synuclein and engineered mice expressing alpha-synuclein mutations. Both of these Aims, animals will receive chronic intermittent L-dopa treatment either during or after acquisition of the learning task to test the effects of dopamine replacement therapy on learning and neuronal activity. In Aim 3, we propose to examine L-dopa induced dyskinesias in rats with 6-OHDA lesions. We will measure the activation of immediate early genes in the striosomes and in the matrix and will correlate the expression patterns with behavioral dyskinesias. We will also perform gene assays using laser-dissected striosome and matrix tissues to measure differential compartmental distributions of downstream genes in relation to dyskinesias. The results of these experiments will yield important knowledge about neural mechanisms underlying two forms of striatal plasticity implicated in parkinsonian syndromes: that related to procedural learning and that leading to the development of L-dopa induced dyskinesia in PD and related movement disorders.