Spatial and temporal pathophysiology of developmental dystonia

项目摘要/摘要 神经和神经精神疾病在世界范围内日益受到关注，因为其后果 通常是致命的，或者充其量也就是让患者丧失能力。一种这样的疾病是肌张力障碍，它 不堪重负的影响有严重运动困难的人，包括疼痛的肌肉过度收缩， 身体扭曲，四肢震颤。尽管最近在识别大脑回路方面做出了努力， 有助于肌张力障碍，以及脑深部刺激(DBS)作为成人治疗的成功， 儿科患者面临着独特的长期健康问题，许多儿童的治疗选择很差 因为疾病发病的时间尚不清楚。这样的障碍出现了，比如开发电路是动态的； 而促进大脑成熟的功能变化为使用大脑深部刺激创造了障碍。 然而，最主要的问题是，我们目前对大脑区域是如何 调节肌张力障碍的回路出现在胚胎和出生后早期。作为第一步 为了更好地定义引发肌张力障碍的发育机制，我们发现 结果是大脑形态发生所需的单个基因Engraed1(EN1)的条件性丢失 在老鼠的严重肌张力障碍中。EN1及其同源基因Engraile2(EN2)是含有同源异型盒的基因 共同控制中脑和后脑的发育。基底节，这部分是 位于中脑的小脑和完全位于后脑的小脑是两个 被认为驱动肌张力障碍病理生理学的主要结构。有趣的是，对EN1的操纵 单独使用时，基底节完好无损，但会改变小脑的环路模式。以小脑为基础 EN1条件表型的焦点，我们认为严重的肌张力障碍起源于遗传- 明确的缺陷扰乱了小脑回路的成熟。我们生成了三个具体目标来测试这一点 体内假说。在Aim1中，我们将使用条件遗传操作与体内实验相结合 电生理学和定量行为范式揭示EN1的时间依赖性 在设定发育性肌张力障碍的严重程度时。在AIM2中，我们将执行特定细胞类型的删除 然后对表现良好的幼鼠进行体内电生理学，以确定 依赖EN1的小脑回路触发早发性肌张力障碍。虽然小脑和 基底节存在于EN1突变体中，目前尚不清楚他们的电路是否错误连接到 无法修复。在Aim3中，我们将使用EN1谱系将光遗传DBS靶向小脑和 基底节，以测试哪个区域恢复了EN1突变体的流动性。然后，我们将为您带来光生生物 刺激对照小鼠的EN1谱系，以测试这些区域中的哪些区域可以在 其他正常幼鼠和成年小鼠。为不治之症设计更好的治疗方案 疾病将改善医疗保健考虑，提高儿科患者的生活质量。

PROJECT SUMMARY/ABSTRACT Neurological and neuropsychiatric diseases are a growing concern worldwide, as the consequences are often lethal, or at best they leave patients incapacitated. One such disease is dystonia, which overwhelms affected people with severe motor difficulties including painful muscle over-contractions, twisting of the body and tremor in the limbs. Despite recent efforts in identifying the brain circuits that contribute to dystonia, as well as the success of deep brain stimulation (DBS) as a therapy for adults, pediatric patients face unique long-term health concerns, with poor treatment options for many kids since the timing of disease onset is unclear. Such barriers arise as developing circuits are dynamic; and functional changes that promote brain maturation create hurdles for using deep brain stimulation. An overarching problem, however, is that we currently have little insight into how the brain regions and circuits that mediate dystonia emerge during embryonic and early postnatal life. As a first step towards better defining the developmental mechanisms that instigate dystonia, we have found that conditional loss of a single gene, engrailed1 (En1), which is required for brain morphogenesis, results in severe dystonia in mice. En1 and its homolog engrailed 2 (En2) are homeobox-containing genes that cooperate to control midbrain and hindbrain development. The basal ganglia, which are partly located in the midbrain, and the cerebellum, which is entirely located within the hindbrain, are the two main structures that are thought to drive dystonia pathophysiology. Intriguingly, manipulations of En1 alone leave the basal ganglia intact, but alter cerebellar circuit patterning. Based on the cerebellar focus of the En1 conditional phenotype, we argue that severe dystonia originates from genetically- defined defects that disrupt cerebellar circuit maturation. We generated three specific aims to test this hypothesis in vivo. In Aim1, we will use conditional genetic manipulations in combination with in vivo electrophysiology and quantitative behavioral paradigms to uncover the temporal dependence of En1 in setting the severity of developmental dystonia. In Aim2, we will perform cell-type specific deletions of En1 and then conduct in vivo electrophysiology in behaving pups to define the neural signatures of the En1-dependent cerebellar circuits that trigger early-onset dystonia. Although the cerebellum and basal ganglia are present in En1 mutants, it is unclear if their circuits are mis-wired to a point that is beyond repair. In Aim3, we will use the En1 lineage to target optogenetic DBS to the cerebellum and basal ganglia to test which region restores mobility in En1 mutants. Then, we will deliver optogenetic stimulation to the En1 lineage in control mice to test which of these regions can initiate dystonia in otherwise normal young and adult mice. Designing better treatment options for incurable motor diseases will improve healthcare considerations and enhance the quality of life for pediatric patients.