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) 是纹状体回路的一个中心元件，但人们对其知之甚少。相当大的 文献强烈表明 ChI 功能障碍与异常运动的发病机制有关，尤其是肌张力障碍 和左旋多巴引起的帕金森病运动障碍。这些研究的一个共同主题是适应不良 塑性变化导致 ChI 输出和连接异常，促进运动功能障碍。的中心目标是 该提案旨在促进对 ChIs 引起的细胞和突触机制的理解 通过在最近验证的模型中采用新颖的选择性遗传和化学策略来治疗运动功能障碍 DYT1 肌张力障碍。 有条件地敲除所有纹状体神经元的 torsinA（使用 Dlx5/6-Cre；“Dlx-CKO”）会导致选择性 背外侧纹状体 ChI 的神经变性。 ChI 变性与幼年发病大致同时发生 这些小鼠的异常扭转运动，并且死后也存在选择性 ChI 异常 来自 DYT1 受试者的组织。这些运动被用于抑制毒蕈碱的相同抗毒蕈碱化合物抑制。 治疗 DYT1 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。幸存的纹状体 ChI 增大且过度兴奋，并接受 异常的突触输入。选择性消融这些幸存的 ChI 可抑制异常扭曲，这意味着 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 的适应不良会导致运动功能障碍。 成功完成拟议的研究将从根本上增进对适应不良的理解 ChI 功能和连接性驱动异常运动的机制，信息非常重要 用于多种纹状体疾病。我们将首先通过测试纹状体 ChI 的必要性来解决我们的假设 通过选择性地恢复这些细胞的torsinA（目标1），果断地消除异常运动产生的功能障碍 超越这些因素之间目前的关联。我们将确定是否出现胆碱能功能障碍 主要来自内在的 ChI 异常或对传入信号反应方式的缺陷（目标 2），并且通过 目标 1 和 2，将进行转化研究（目标 3），测试是否直接调节存活的活动 ChI 可以抑制肌张力障碍样运动。因此，该提案非常重要，因为它将定义一个 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.