Cell Type Specific Genetic Manipulation to Dissect Cholinergic Interneuron Function and Plasticity in a Symptomatic Model of DYT1 Dystonia

项目概要/摘要 胆碱能神经元（ChIs）是纹状体回路的中心但知之甚少的元件。相当 文献强烈暗示ChI功能障碍在异常运动的发病机制中，特别是在肌张力障碍中 和帕金森病中左旋多巴诱导的运动障碍。这些研究的一个共同主题是， 可塑性变化导致异常的ChI输出和连接，促进运动功能障碍。的中心目标 这一建议是为了促进对ChIs引起的细胞和突触机制的理解， 运动功能障碍，采用新的选择性遗传和化学策略，在最近验证的模型， DYT 1肌张力障碍。 来自所有纹状体神经元的扭转蛋白A的条件性敲除（使用Dlx 5/6-Cre;“Dlx-CKO”）导致选择性的 背外侧纹状体ChI神经变性。ChI退化发生在幼年期， 在这些小鼠的异常扭转运动，并选择性ChI异常也存在于死后 DYT 1受试者的组织。这些运动被用来抑制相同的抗毒蕈碱化合物 治疗DYT 1肌张力障碍患者，建立模型治疗有效性，并建议共享 人类肌张力障碍的病理生理学存活的纹状体ChI增大且过度兴奋， 异常的突触输入选择性消融这些存活的ChI抑制了异常扭曲， 这些细胞是异常运动的关键因素。根据这些数据，我们假设， 幸存的ChI适应不良导致运动功能障碍。 成功完成拟议的研究将从根本上推进对适应不良的理解 ChI功能和连接驱动异常运动的机制，信息非常重要 多发性纹状体疾病我们将首先通过检验纹状体ChI的必要性来解决我们的假设。 通过选择性地将扭转蛋白A恢复到这些细胞中， 超越这些因素之间的现有关联。我们将确定是否出现胆碱能功能障碍 主要来自内在的ChI异常或缺陷，他们如何回应传入（目标2），并告知 目的1和2，将进行转化研究（目的3），测试是否直接调节存活的活性， 气可以抑制肌张力障碍样运动。因此，这项建议非常重要，因为它将界定一个 基于电路的运动功能障碍模型，将为靶向治疗的设计提供信息。

Project Summary/Abstract Cholinergic neurons (ChIs) are a central but poorly understood element of striatal circuitry. A considerable literature strongly implicates ChI dysfunction in the pathogenesis of abnormal movements, especially in dystonia and levodopa-induced dyskinesias in Parkinson disease. A common theme of these studies is that maladaptive plastic changes cause aberrant ChI output and connectivity, promoting motor dysfunction. The central goal of this proposal is to advance understanding of the cellular and synaptic mechanisms through which ChIs cause motor dysfunction by employing novel selective genetic and chemical strategies in a recently validated model of DYT1 dystonia. Conditional Knock Out of torsinA from all striatal neurons (using Dlx5/6-Cre; “Dlx-CKO”) causes selective neurodegeneration of dorsolateral striatal ChI. ChI degeneration occurs roughly coincident with the juvenile onset of abnormal twisting movements in these mice, and selective ChI abnormalities are also present in postmortem tissue from DYT1 subjects. These movements are suppressed by the same anti-muscarinic compounds used to treat patients with DYT1 dystonia, establishing model therapeutic validity and suggesting shared pathophysiology with human dystonia. Surviving striatal ChIs are enlarged and hyperexcitable, and receive aberrant synaptic inputs. Selective ablation of these surviving ChI suppresses abnormal twisting, implicating these cells as key contributors to abnormal movements. Based on these data, we hypothesize that maladaptations in surviving ChIs drive motor dysfunction. Successful completion of the proposed studies will fundamentally advance understanding of maladaptive mechanisms whereby ChI function and connectivity drive abnormal movements, information highly significant for multiple striatal diseases. We will first address our hypothesis by testing the necessity of striatal ChI dysfunction in abnormal movement generation by selectively restoring torsinA to these cells (Aim 1), decisively moving beyond the current association between these factors. We will determine if cholinergic dysfunction arises primarily from intrinsic ChI abnormalities or defects in how they respond to afferents (Aim 2), and, informed by Aims 1 and 2, will pursue translational studies (Aim 3) testing whether directly modulating the activity of surviving ChIs can suppress dystonic-like movements. This proposal is therefore highly signifiant because it will define a circuit-based model of motor dysfunction that will inform the design of targeted therapeutics.