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在患者的壮年时期开始的致残的神经疾病。科学家们已经确定了与这种疾病的一些遗传形式有关的基因，但对其病理生理学知之甚少，目前的治疗方法有限且具有症状。由于这些患者的大脑没有表现出神经路径的逻辑异常，因此假设肌张力障碍是一种电路活动异常的疾病。这项提议旨在解剖肌张力障碍小鼠模型中的关键运动控制中心之一--纹状体的电路。在研究纹状体环路时，我们希望为肌张力障碍和其他多动症的治疗发展确定新的靶点。我们建议使用几种新的工具来更好地了解肌张力障碍患者的电路功能障碍。首先，我们计划使用一种新的人类肌张力障碍的小鼠模型，阵发性非运动性运动障碍(PNKD)，这是极少数概括人类肌张力障碍临床特征的动物模型之一。其次，我们计划使用一种新的实验工具--个体遗传学，它允许研究人员控制大脑中特定细胞群体的活动。在目标1中，我们将利用个体发生和体内电生理学来鉴定清醒行为的PNKD小鼠纹状体神经元的病理放电模式，并首次区分直接通路和间接通路神经元活动的差异是如何导致肌张力障碍的。在目标2中，我们将使用体外电生理学来确定PNKD小鼠体内病理放电模式的细胞和突触底物。最后，在目标3中，我们将利用我们在体内和体外对肌张力障碍小鼠的研究成果，通过在行为动物中使用个体发育来确定哪些方面的异常纹状体活动是导致肌张力障碍的必要条件和充分条件。我们还将通过个体遗传学改变纹状体的放电模式，以减少或消除PNKD小鼠的肌张力障碍症状。总体而言，我们希望这一系列研究不仅将阐明长期以来关于肌张力障碍患者基底神经节回路功能障碍的理论，而且将为治疗开发提供新的领域。我是一名内科科学家，坚定地致力于学术神经学的职业生涯，专注于确定神经疾病的电路基础。我将神经生理学的博士和博士后培训与行为神经学和运动障碍的子专业培训结合起来。这项研究提案所涉及的职业发展将把我的技能带到神经疾病的小鼠模型中，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。这项建议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拨款申请，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.