Function and Regulation of ALDH1A1-positive Nigrostriatal Dopaminergic Neurons in Motor Control and Parkinson's disease

ALDH1A1 阳性黑质纹状体多巴胺能神经元在运动控制和帕金森病中的功能和调节

基本信息

批准号：
10913158
负责人：
Huaibin Cai
金额：
$ 165.99万
依托单位：
NATIONAL INSTITUTE ON AGING
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10913158
关键词：
Address Affect Area Axon Behavior Behavior Control Behavioral Binding Brain Calcium Calcium Signaling Chloride Channels Corpus striatum structure Coupled Crossbreeding Cues Development Dopamine Etiology Failure Feedback Fiber Optics GABA-B Receptor Genetic Glutamates Head Image Implant Investigation Knock-in Mouse Knowledge Learning Light Maps Mediating Memory Methods Molecular Motivation Motor Motor Skills Movement Mus NMDA receptor A1 Neurons Neurotransmitters Outcome Parkinson Disease Pathogenesis Patients Pattern Performance Physiological Play Population Predisposition Process Regulation Research Resolution Rewards Role Sensory Signal Transduction Silicones Slice Source Substantia nigra structure Task Performances Techniques Time Viral Vector Walking aldehyde dehydrogenases cytotoxic designer receptors exclusively activated by designer drugs dopaminergic neuron genetic manipulation in vivo insight light gated motor control motor learning motor skill learning neuronal excitability novel therapeutic intervention optical fiber optogenetics pars compacta presynaptic receptor receptor expression response selective expression temporal measurement treadmill two-photon virtual

项目摘要

To investigate the activity patterns of ALDH1A1+ DANs during motor skill learning and sensorimotor behavioral control, we will conduct single-unit spiking activity recordings from DANs in the ventral SNc of Aldh1a1CreERT2 mice. We will utilize optotrodes equipped with either silicone laminar arrays or microwire bundles during an adaptive motor learning task, where head-fixed mice learn to walk on a spheric treadmill. Subsequently, mice will undergo a sensorimotor operant task of virtual navigation on the treadmill with precise sensory cues and feedback to forage for rewards. To identify ALDH1A1+ DANs during recordings, we will employ the optogenetic tagging method. Our aim is to examine how the activity of ALDH1A1+ and ALDH1A1-negative (ALDH1A1) DANs is modulated at different epochs and stages of motor learning. We will also investigate burst activity related to classic reward prediction errors in these neurons, particularly in response to predictive sensory cues and various trial outcomes. These results will help determine how DAN activity from molecularly defined classes contributes to motor learning and behavioral control. To achieve high temporal resolution, crucial for conveying critical behavioral information, we will record spiking activity from DANs. Alternatively, we will use deep brain calcium two-photon imaging, a recently acquired technique, which will allow us to investigate plasticity in ALDH1A1+ DANs during learning. This method will enable us to follow the activity of the same ALDH1A1+ DAN ensemble throughout the entire learning process. The subcellular spatial resolution offered by calcium imaging will aid in identifying sources of learning-related signals to these neurons, including changes in specific input strength in dendritic compartments during learning and task performance. Although calcium signals have slower dynamics than spikes, certain aspects of DAN activity in the sub-second scale may be sufficient for behavioral control, such as changes in tonic spike rate or magnitude of their axonal dopamine release. To establish causality between ALDH1A1+ DAN activity and motor learning performance, we will manipulate somatic spiking activity and axonal dopamine release using optogenetics and chemogenetics methods. By expressing light-gated chloride channels, such as JAWS, in these neurons via Cre-dependent viral vectors, we can transiently inhibit somatic activity using light delivered through implanted optic fibers in the SNc. Precise temporal patterns of ALDH1A1+ DAN spiking activity, especially burst firing, will be time-locked to specific behavioral epochs to determine their causal contribution to learning. Additionally, facilitatory or inhibitory chemogenetic receptors, known as DREADDs, will be expressed in these neurons to allow bidirectional control of their excitability during task performance. As axonal dopamine release often has region-specific regulation mechanisms independent from somatic spiking, we will transiently suppress axonal dopamine release of ALDH1A1+ DANs in one of their projected areas using light-activated Gi/o-coupled receptors expressed in ALDH1A1+ DAN axons. The resulting learning efficacy and behavioral changes from these manipulations will be compared with corresponding sham control mice to draw conclusions. This approach will enable us to determine the causal roles of specific aspects of ALDH1A1+ DAN neuronal activity in motor learning and behavioral control. For example, reduced excitability of these neurons may delay motor learning, while increased excitability could expedite learning. Timing of burst activity in ALDH1A1+ DANs may be pivotal for learning, as inhibiting these neurons at the movement initiation could result in more motor errors, while inhibition during the presence of sensory cues may lead to failure in reward association. Suppression of their dopamine release in the striatum is also expected to affect learning, potentially in a learning-stage dependent manner. To gain further circuit insight, we will genetically manipulate specific inputs to these neurons. By crossbreeding Aldh1a1CreERT2 mice with Grin1-LoxP KI mice, we can selectively disrupt glutamate-mediated excitatory inputs to the ALDH1A1+ DANs. Preliminary results from the resulting Grin1 cKO mice suggest that the glutamatergic afferent activity at ALDH1A1+ DANs may not be required for motor skill learning but could still be involved in other aspects of learning. As ALDH1A1+ SNc DANs display distinct rebound activity in response to GABA-B receptor (Gabbr1)-mediated inhibitory inputs from dSPNs, we are currently developing Gabbr1 cKO mice to selectively disrupt Gabbr1 expression in ALDH1A1+ DANs. These Gabbr1 cKO mice will provide critical insights into the contribution of Gabbr1-mediated rebound and burst activity in ALDH1A1+ DAN-dependent motor skill learning.

为了研究 ALDH1A1+ DAN 在运动技能学习和感觉运动行为控制过程中的活动模式，我们将对 Aldh1a1CreERT2 小鼠腹侧 SNc 中的 DAN 进行单单位尖峰活动记录。我们将在自适应运动学习任务中使用配备有硅层状阵列或微线束的光极，其中头部固定的小鼠学习在球形跑步机上行走。随后，小鼠将在跑步机上进行虚拟导航的感觉运动操作任务，并根据精确的感觉线索和反馈来寻找奖励。为了在记录过程中识别 ALDH1A1+ DAN，我们将采用光遗传学标记方法。我们的目的是研究 ALDH1A1+ 和 ALDH1A1-阴性 (ALDH1A1) DAN 的活性如何在运动学习的不同时期和阶段受到调节。我们还将研究与这些神经元中经典奖励预测错误相关的爆发活动，特别是对预测性感官线索和各种试验结果的反应。这些结果将有助于确定分子定义类别的 DAN 活性如何促进运动学习和行为控制。为了实现对于传达关键行为信息至关重要的高时间分辨率，我们将记录 DAN 的尖峰活动。或者，我们将使用深部脑钙双光子成像，这是一种最近获得的技术，这将使我们能够在学习过程中研究 ALDH1A1+ DAN 的可塑性。这种方法将使我们能够在整个学习过程中跟踪同一 ALDH1A1+ DAN 整体的活动。钙成像提供的亚细胞空间分辨率将有助于识别这些神经元的学习相关信号的来源，包括学习和任务执行期间树突区室中特定输入强度的变化。尽管钙信号的动态比尖峰慢，但亚秒级 DAN 活性的某些方面可能足以进行行为控制，例如强直尖峰速率的变化或其轴突多巴胺释放的幅度。为了建立 ALDH1A1+ DAN 活动与运动学习表现之间的因果关系，我们将使用光遗传学和化学遗传学方法操纵体细胞尖峰活动和轴突多巴胺释放。通过 Cre 依赖性病毒载体在这些神经元中表达光门控氯离子通道（例如 JAWS），我们可以利用通过 SNc 中植入的光纤传递的光来暂时抑制体细胞活动。 ALDH1A1+ DAN 尖峰活动的精确时间模式，尤其是突发放电，将被锁定在特定的行为时期，以确定它们对学习的因果贡献。此外，促进性或抑制性化学遗传受体（称为 DREADD）将在这些神经元中表达，以允许在任务执行过程中双向控制其兴奋性。由于轴突多巴胺释放通常具有独立于体细胞尖峰的区域特异性调节机制，因此我们将使用 ALDH1A1+ DAN 轴突中表达的光激活 Gi/o 偶联受体暂时抑制 ALDH1A1+ DAN 在其投影区域之一的轴突多巴胺释放。这些操作产生的学习效率和行为变化将与相应的假对照组小鼠进行比较，以得出结论。这种方法将使我们能够确定 ALDH1A1+ DAN 神经元活动的特定方面在运动学习和行为控制中的因果作用。例如，这些神经元的兴奋性降低可能会延迟运动学习，而兴奋性增加可能会加速学习。 ALDH1A1+ DAN 中爆发活动的时间可能对于学习至关重要，因为在运动开始时抑制这些神经元可能会导致更多的运动错误，而在感觉提示存在期间的抑制可能会导致奖励关联失败。纹状体中多巴胺释放的抑制预计也会影响学习，可能以学习阶段依赖的方式。为了获得进一步的电路洞察力，我们将对这些神经元的特定输入进行基因操纵。通过将 Aldh1a1CreERT2 小鼠与 Grin1-LoxP KI 小鼠杂交，我们可以选择性地破坏谷氨酸介导的 ALDH1A1+ DAN 的兴奋性输入。由此产生的 Grin1 cKO 小鼠的初步结果表明，ALDH1A1+ DAN 的谷氨酸传入活动可能不是运动技能学习所必需的，但仍可能参与学习的其他方面。由于 ALDH1A1+ SNc DAN 对来自 dSPN 的 GABA-B 受体 (Gabbr1) 介导的抑制输入做出反应，表现出明显的反弹活性，因此我们目前正在开发 Gabbr1 cKO 小鼠，以选择性破坏 ALDH1A1+ DAN 中的 Gabbr1 表达。这些 Gabbr1 cKO 小鼠将为 Gabbr1 介导的反弹和爆发活动在 ALDH1A1+ DAN 依赖性运动技能学习中的贡献提供重要的见解。