Optogenetic dissection of striatal circuits in a mouse model of human dystonia

描述（由申请人提供）：原发性肌张力障碍是开始于患者生命黄金期的致残性神经系统疾病。科学家们已经确定了参与某些遗传性疾病的基因，但对病理生理学知之甚少，目前的治疗方法有限，而且本质上是对症的。由于这些患者的大脑没有显示出神经病理学异常，因此假设肌张力障碍是一种异常回路活动的疾病。这项建议的目的是解剖电路的关键运动控制中心之一，纹状体，在小鼠模型的张力障碍。在研究纹状体电路，我们希望确定新的目标，治疗发展肌张力障碍以及其他运动过度性运动障碍。我们建议使用一些新的工具，以更好地了解电路功能障碍的肌张力障碍。首先，我们计划使用一种新的人类肌张力障碍小鼠模型，阵发性非运动诱发性运动障碍（PNKD），这是极少数的动物模型，概括了人类肌张力障碍的临床特征之一。第二，我们计划采用一种新的实验工具，个体发生学，它允许研究人员控制大脑中特定细胞群的活动。在目标1中，我们将使用个体发育和体内电生理学来识别清醒行为PNKD小鼠中纹状体神经元的病理性放电模式，并首次区分直接通路和间接通路神经元的活性差异如何导致肌张力障碍。在目标2中，我们将使用体外电生理学来确定PNKD小鼠体内鉴定的病理性放电模式的细胞和突触底物。最后，在目标3中，我们将从肌张力障碍小鼠的体内和体外研究中了解到，通过在行为动物中使用个体发育来确定异常纹状体活动的哪些方面是引起肌张力障碍所必需和充分的。我们还将个体遗传学修饰纹状体放电模式，以减少或消除PNKD小鼠的肌张力障碍症状。总的来说，我们希望这一系列的研究不仅能阐明长期以来关于肌张力障碍中基底神经节回路功能障碍的理论，而且能为治疗发展开辟新的领域。我是一名医生兼科学家，致力于学术神经病学的职业生涯，专注于确定神经系统疾病的电路基础。我将联合收割机博士和博士后的神经生理学培训与行为神经学和运动障碍的亚专业培训相结合。这项研究提案所涉及的职业发展将把我的技能带入神经系统疾病的小鼠模型，并培养尖端的神经生理学和光遗传学技术，作为理解和破坏神经活动异常模式的手段。本提案中所涉及的指导将为我提供科学和专业资源，以继续我作为研究人员的发展，使我能够提交有竞争力的资助申请，并在未来领导我自己的实验室。

DESCRIPTION (provided by applicant): Primary dystonias are disabling neurological conditions which begin in the prime of patients' lives. Scientists have identified genes involved i some inherited forms of the disease, but little is known about the pathophysiology, and at present treatments is limited and symptomatic in nature. As the brains of such patients show no neuropath logical abnormalities, it is hypothesized that dystonia is a disease of abnormal circuit activity. This proposal is aimed at dissecting the circuitry of one of the key movement control centers, the striatum, in a mouse model of dystonia. In examining the striatal circuitry, we hope to identify new targets for therapeutic development in dystonia as well as other hyperkinetic movement disorders. We propose to use several novel tools to better understand circuit dysfunction in dystonia. First, we plan to use a new mouse model of a human dystonia, paroxysmal nonkinesigenic dyskinesia (PNKD), which is one of very few animal models that recapitulate the clinical features of human dystonia. Second, we plan to employ a new experimental tool, ontogenetic, which allows researchers to control the activity of specific cell populations in the brain. In Aim 1, we will use ontogenetic and in vivo electrophysiology to identify the pathological firing patterns of striatal neurons in awake-behaving PNKD mice, and for the first time distinguish how differences in the activity of direct-pathway and indirect- pathway neurons contribute to dystonia. In Aim 2, we will use in vitro electrophysiology to determine the cellular and synaptic substrate for the pathological firing patterns identified in PNKD mice in vivo. Finally, in Aim 3, we will take what we have learned from both in vivo and in vitro studies of dystonic mice to determine what aspects of aberrant striatal activity are necessary and sufficient to cause dystonia, by using ontogenetic in behaving animals. We will also ontogenetically modify striatal firing patterns to reduce or eliminate the symptoms of dystonia in PNKD mice. Overall, we are hopeful this line of research will not only shed light on long-held theories about basal ganglia circuit dysfunction in dystonia, but will yield new areas fo therapeutic development. I am a physician-scientist with a strong commitment to a career in academic neurology, focused on identifying the circuit basis of neurological disease. I combine PhD and postdoctoral training in neurophysiology with subspecialty training in behavioral neurology and movement disorders. The career development entailed in this research proposal will bring my skills into mouse models of neurological disease and cultivate cutting-edge neurophysiological and optogenetic techniques as a means of understanding and disrupting abnormal patterns of neural activity. The mentoring entailed in this proposal will provide me the scientific and professional resources to continue my own development as an investigator, enabling me to submit competitive grant applications and lead my own laboratory in the future.