Striatopallidal GABAergic Signaling in Mouse Models of Parkinson's Disease

描述（由申请人提供）：帕金森病（PD）是美国第二常见的神经退行性疾病。PD的核心运动症状可归因于中脑多巴胺能神经元的变性和基底神经节中神经元活性的改变。在PD患者和灵长类PD模型中，基底神经节的球状体（GPe）外段的神经元以同步的高频节律性爆发放电。这种病理生理活性被认为是PD患者运动迟缓、运动不能和僵硬的原因。过去二十年来主导该领域的流行模型假设多巴胺耗尽后纹状体（CPu-GPe）GABA能抑制输入GPe升高。然而，这一猜想尚未在实验上得到证实。特别是调节CPu-GPe突触传递的细胞和分子决定因素尚未完全了解。更重要的是，它们在疾病状态下的适应性仍然完全未被探索。在这个建议中，我们假设，前和突触后的CPu-GPe的变化发生作为基底神经节电路内的多巴胺能神经支配的结果，有助于运动症状的疾病。通过在PD小鼠模型中混合电生理学、药理学、转录组学和免疫细胞化学分析，本项目追求三个具体目标，以解决GABA能输入GPe的基本机制。使用小鼠模型的PD，我们的目标是确定并最终调和特定的分子变化，在纹状体突触。我们的目的是：1）描述纹状体-体突触的生理特性。2)研究GPe神经元中GABAA受体亚型的表达。3)目的：研究纹状体苍白球输入与GPe神经元内禀电导之间的相互作用。 公共卫生相关性：这些研究旨在纠正晚期PD中功能失调的大脑活动。本课题的成功实现不仅为晚期PD的治疗提供了新的思路，也为药物治疗开辟了新的途径。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is the second most common neurodegenerative disease in the U.S. The core motor symptoms of PD are attributable to the degeneration of the mesencephalic dopaminergic neurons and alterations in the activity of neurons in the basal ganglia. In PD patients and in primate PD models, neurons in the external segment of the globus (GPe) of the basal ganglia spike in synchronous, high frequency rhythmic bursts. This pathophysiological activity is thought to be responsible for bradykinesia, akinesia, and rigidity in PD patients. The prevailing model that has dominated the field for the last two decades assumes an elevation in striatopallidal (CPu-GPe) GABAergic inhibitory input to the GPe following dopamine depletion. However, this conjecture has not been experimentally established. In particular the cellular and molecular determinants that regulate the transmission at the CPu-GPe synapse have not been fully understood. More importantly, their adaptations in disease state remain completely unexplored. In this proposal, we hypothesize that both pre- and post-synaptic alterations of the CPu-GPe occur as a result of dopaminergic denervation within the basal ganglia circuit, contributing to the motor symptoms of the disease. By blending electrophysiological, pharmacological, transcriptomic, and immunocytochemical analyses in mouse models of PD, this project pursues three specific aims addressing the basic mechanisms underlying GABAergic input to the GPe. Using mouse models of PD, we aim to identify and ultimately reconcile specific molecular changes in the striatopallidal synapse. Our aims are: 1) To characterize the physiological properties of the striatopallidal synapse. 2) To characterize the GABAA receptor subtypes expressed in GPe neurons. 3) To characterize the interaction between striatopallidal input and intrinsic conductances of GPe neurons. PUBLIC HEALTH RELEVANCE: These studies are aimed at correcting dysfunctional brain activity in late stage PD. The successful attainment of our aims could not only provide a novel therapy for late stage PD but open new avenues for pharmacological treatment.