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

• 批准号: 10688870
• 负责人: Huaibin Cai
• 金额: $ 191.06万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 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/10688870
• 关键词: Area; Axon; Behavior; Behavior Control; Behavioral; Brain; Calcium; Calcium Signaling; Chemicals; Chloride Channels; Corpus striatum structure; Cues; Dopamine; Dorsal; Etiology; Failure; Feedback; Fiber Optics; GABA-B Receptor; Glutamates; Head; Image; Impairment; Implant; Knock-in Mouse; Lead; Learning; Light; Maps; Mediating; Memory; Methods; Molecular; Motivation; Motor; Motor Skills; Movement; Mus; NMDA receptor A1; Neurons; Outcome; Parkinson Disease; Pathogenesis; Patients; Pattern; Performance; Physiological; Population; Process; Regulation; Research; Resolution; Rewards; Role; Rotarod Performance Test; Sensory; Signal Transduction; Silicones; Slice; Source; Speed; Substantia nigra structure; Task Performances; Time; Viral Vector; Walking; aldehyde dehydrogenases; cytotoxic; designer receptors exclusively activated by designer drugs; dopaminergic neuron; experimental study; genetic manipulation; in vivo; insight; light gated; motor control; motor learning; motor skill learning; neuronal cell body; optogenetics; presynaptic; receptor; response; sample fixation; selective expression; temporal measurement; treadmill; two-photon; virtual

To reveal the activity pattern of ALDH1A1+ DANs during motor skill learning and sensorimotor behavioral control, we will record single-unit spiking activity from DANs in the ventral SNc of Aldh1a1CreERT2 mice, using optotrode equipped with either silicone laminar arrays or microwire bundles in an adaptive motor learning task, as head-fixed mice learn to walk on a spheric treadmill with head fixation. After learning the motor skill of adaptive walk, mice will proceed to a sensorimotor operant task of virtual navigation on the treadmill with precise sensory cues and feedback to forage for reward. Identification of ALDH1A1+ DANs during recording will be accomplished using the optogenetic tagging method. We will determine how 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 the classic reward prediction errors in these neurons in the presence of predictive sensory cues and various trial outcomes. The results will allow us to determine how DAN activity from molecularly defined classes contribute to motor learning and behavioral control. We would expect both burst and tonic activity of ALDH1A1+ DANs to show elevated spike rate during learning which correlates with behavioral improvement. We also expect ALDH1A1+ DANs display unique pause and rebound firing following transient inhibition from striatal inputs that could be essential for learning to avoid negative outcomes and motor errors. Recording spiking activity has the advantage of high temporal resolution when instantaneous timing of spikes is needed to convey critical behavioral information, such as spike timing in DAN bursts to track behavioral epochs. An alternative method for recording DAN activity is using our recently acquired deep brain calcium two-photon imaging, which also allows us to investigate plasticity of DANs in learning by following the activity of the same ALDH1A1+ DAN ensemble over the entire course of learning. The capacity of subcellular spatial resolution in imaging could also help to identify sources of learning related signals to these neurons by visualizing changes in specific input strength in dendritic compartments during learning and task performance. The calcium signals have slower dynamics than spikes, but certain aspects of DAN activity in sub-second scale might be sufficient for behavioral control, such as changes of tonic spike rate or magnitude of their axonal dopamine release. To establish the causality between ALDH1A1+ DAN activity and motor learning performance, we will manipulate somatic spiking activity and axonal dopamine release of ALDH1A1+ DANs with different timescales during the same motor skill and sensorimotor learning tasks described in the recording experiments, using optogenetics and chemogenetics methods. Light-gated chloride channels, such as JAWS, will be expressed in these neurons using Cre-dependent viral vectors to allow transient inhibition of their somatic activity via light delivered through implanted optic fibers in the SNc. Timing of the optogenetic inhibition of soma will be time-locked to specific behavioral epochs to determine how precise temporal patterns of ALDH1A1+ DAN spiking activity, particularly the burst firing, causally contributes to learning. To determine how the longer time scale ALDH1A1+ DAN excitability contribute to learning, facilitatory or inhibitory chemogenetic receptor DREADDs will be expressed in these neurons to allow bidirectional control of their excitability during the task performance. Axonal dopamine release often has region-specific regulation mechanisms independent from somatic spiking. To investigate how dopamine released by these neurons in specific target areas contribute to learning, we will transiently suppress axonal dopamine release of ALDH1A1+ DANs in one of their projected areas. Light activated Gi/ocoupled receptors will be expressed in ALDH1A1+ DAN axons, where their dopamine release can be inhibited by light delivered through an implanted optic fiber at various subregions of the dorsal striatum. The resulting learning efficacy and behavioral changes from all these manipulations will be compared with corresponding sham control mice to draw conclusions. The results will allow us to determine the causal roles of specific aspects of ALDH1A1+ DAN neuronal activity in motor learning and behavioral control. If overall dopamine release resulted from ALDH1A1+ DAN activity over the extended behavioral period contributes to learning, we would expect that reduced excitability of these neurons delays motor learning, while increased excitability could speed the learning. If timing of burst activity of ALDH1A1+ DANs is pivotal in learning, we would expect inhibiting these neurons at the movement initiation causes more motor errors, while inhibiting them at the presence of sensory cues may lead to failure in reward association. Suppression of their dopamine release in the striatum is also expected to impair learning that maybe learning-stage dependent. To gain more circuit insight, an alternative strategy to investigate causal roles of ALDH1A1+ DAN neuronal activity in motor learning is genetically manipulate specific inputs to these neurons. Toward this direction, we had crossbred Aldh1a1CreERT2 mice with Grin1-LoxP KI mice to selectively disrupt the glutamate-mediated excitatory inputs to the ALDH1A1+ DANs. The resulting Grin1 cKO mice performed normally in the rotarod test, suggesting the glutamatergic afferent activity at ALDH1A1+ DANs is not required for the motor skill learning, but may still be involved in other aspects of learning. As the ALDH1A1+ SNc DANs display distinct rebound activity in response to the GABA-B receptor (Gabbr1)-mediated inhibitory inputs from dSPNs, we are in the middle of developing Gabbr1 cKO mice to selectively disrupt the expression of Gabbr1 in ALDH1A1+ DANs. This line of Gabbr1 cKO mice will allow us to critically evaluate the contribution of Gabbr1-mediated rebound and burst activity in ALDH1A1+ DAN-dependent motor skill learning.

To reveal the activity pattern of ALDH1A1+ DANs during motor skill learning and sensorimotor behavioral control, we will record single-unit spiking activity from DANs in the ventral SNc of Aldh1a1CreERT2 mice, using optotrode equipped with either silicone laminar arrays or microwire bundles in an adaptive motor learning task, as head-fixed mice learn to walk on a spheric treadmill with head固定。在学习了自适应步行的运动技能之后，小鼠将通过精确的感觉线索进行虚拟导航的感觉运动操作任务，并反馈以寻求奖励。记录过程中ALDH1A1+ DAN的识别将使用光遗传学标记方法完成。我们将确定如何在运动学习的不同时期和阶段调制ALDH1A1+和ALDH1A1阴性（ALDH1A1）阴性的活动。我们还将在存在预测性感觉线索和各种试验结果的情况下研究与这些神经元中经典奖励预测错误有关的爆发活动。结果将使我们能够确定来自分子定义类别的DAN活动如何有助于运动学习和行为控制。我们希望ALDH1A1+ DAN的爆发和补品活性在学习过程中表现出升高的峰值率，这与行为改善相关。我们还期望ALDH1A1+ DAN显示出独特的停顿和反弹射击，这是纹状体输入的短暂抑制作用，这对于避免避免负面结果和运动误差至关重要。 当需要尖峰的瞬时计时来传达关键的行为信息时，例如，记录尖峰活动具有高时间分辨率的优势，例如在dan爆发中的尖峰时序以跟踪行为时期。记录DAN活动的另一种方法是使用我们最近获得的深脑钙两光子成像，这也使我们能够通过在整个学习过程中遵循相同的ALDH1A1+ DAN集合的活性来研究DAN的学习中的可塑性。亚细胞空间分辨率在成像中的能力也可以帮助通过在学习和任务性能过程​​中可视化树突舱中的特定输入强度的变化来识别与这些神经元相关的信号的来源。钙信号的动力学比尖峰具有较慢的动力学，但是以下尺度的DAN活性的某些方面可能足以控制行为控制，例如强调峰值速率的变化或轴突多巴胺释放的大小。 为了确定ALDH1A1+ DAN活动与运动学习表现之间的因果关系，我们将操纵体细胞尖峰活动和在相同的运动技能和感觉运动技能和感觉运动学习任务中使用不同的时间尺度的ALDH1A1+ DAN的轴突多巴胺释放，并使用Optogenetics和Chemogenetics Metterss进行了录音实验中所述。光门控氯化物通道（例如下颌）将在这些神经元中使用CRE依赖性病毒载体在这些神经元中表达，以通过SNC中的植入的光纤纤维传递的光线抑制其体细胞活性。光遗传学抑制的时机将被锁定到特定的行为时代，以确定Aldh1a1+ Dan Spiking活动的精确时间模式，尤其是爆发的爆发，有助于有助于学习。为了确定较长的时间尺度ALDH1A1+ DAN兴奋性如何有助于学习，在这些神经元中表达促进性或抑制性化学发生受体恐怖，以允许在任务执行过程中对其兴奋性的双向控制。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。为了调查这些神经元在特定目标区域中释放的多巴胺如何有助于学习，我们将暂时抑制Aldh1A1+ DAN的轴突多巴胺在其预计区域之一中的释放。光活化的GI/OCOUPLED受体将在ALDH1A1+ DAN轴突中表达，在该轴突中，通过在背侧纹状体的各个区域通过植入的光纤传递的光可以抑制它们的多巴胺释放。将所有这些操作的学习功效和行为变化与相应的假对照小鼠进行比较，以得出结论。结果将使我们能够确定ALDH1A1+ DAN神经元活动在运动学习和行为控制中的特定方面的因果关系。如果整体多巴胺释放是由ALDH1A1+ DAN在延长的行为期间有助于学习的，我们希望这些神经元的兴奋性降低会延迟运动学习，而提高的兴奋性可以加快学习的速度。如果ALDH1A1+ DAN的爆发活动的时机在学习中是关键的，那么我们希望在运动启动下抑制这些神经元会导致更多的运动误差，同时在感觉线索存在下抑制它们可能会导致奖励关联失败。预计他们在纹状体中释放多巴胺的释放也可能会损害学习阶段的学习。 为了获得更多的电路见解，一种研究ALDH1A1+ DAN神经元活性在运动学习中的因果关系作用的替代策略是对这些神经元的遗传操作。朝这个方向朝着grin1-loxp ki小鼠杂交aldh1a1creert2小鼠，有选择地破坏谷氨酸介导的兴奋性输入到aldh1a1+ dans。在Rotarod测试中正常执行的GRIN1 CKO小鼠，表明运动技能学习不需要Aldh1a1+ dans的谷氨酸能传入活动，但仍可能参与学习的其他方面。由于ALDH1A1+ SNC DAN表现出对GABA-B受体（GABBR1）介导的DSPN介导的抑制性输入的明显反弹活性，因此我们正处于开发GABBR1 CKO小鼠中以选择性地破坏Aldh1a1+ Dans中GABBR1的表达。这条GABBR1 CKO小鼠将使我们能够批判性地评估GABBR1介导的反弹和ALDH1A1+ DAN依赖性运动技能学习中的爆发活动的贡献。