Intact Circuit Assessment of Aging Dopamine Neurons vis Optogenetics and CLARITY

老化多巴胺神经元的完整电路评估与光遗传学和清晰度

• 批准号: 8712256
• 负责人: Viviana Gradinaru
• 金额: $ 37.46万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8712256
• 关键词: Accounting; Affect; Age; Aging; Alzheimer' s Disease; Anatomy; Area; Behavior; Behavioral; Brain; Brain Diseases; Brain Mapping; Cell Nucleus; Cell physiology; Cells; Cognition; Dependence; Development; Disease; Dopaminergic Cell; Electrophysiology (science); Frequencies; Genetic; Glutamates; Grouping; Heterogeneity; Immunohistochemistry; Individual; Laboratories; Life Expectancy; Light; Link; Literature; Location; Maps; Measures; Methods; Midbrain structure; Motor; Movement; Nerve Degeneration; Neuroanatomy; Neurobiology; Neurons; Neurosciences; Nutritional; Opsin; Parkinson Disease; Pathway interactions; Pattern; Phenotype; Positioning Attribute; Predisposition; Process; Property; Proteins; Quality of life; Rattus; Reporting; Research; Resistance; Rodent; Role; Signal Transduction; Slice; Specific qualifier value; Specificity; Speed; Structure of subthalamic nucleus; Substantia nigra structure; Synapses; System; Techniques; Testing; Time; Transgenic Organisms; Tyrosine 3-Monooxygenase; Ventral Tegmental Area; Work; age related; aged; aging brain; base; cell type; dopaminergic neuron; effective therapy; in vivo; innovation; microbial; millisecond; motor deficit; neural circuit; neuronal excitability; neurotransmission; normal aging; optogenetics; pars compacta; promoter; protein expression; public health relevance; relating to nervous system; research study; response; stem; targeted delivery; tool

DESCRIPTION (provided by applicant): During aging, motor function declines, with deficits in fine and fast movement and coordination. Experimental studies associate age-dependent motor deficits with the malfunction of dopaminergic (DA) pathway, which originates in the substantia nigra pars compacta (SNc). However we do not understand how the activity of DA neurons varies throughout aging in the different tiers of nigral neurons in vivo, what type of activity changes precede neurodegeneration, how these activity changes affect behavior, and whether restoring perturbed activity can delay neurodegeneration and/or behavioral deficits. To characterize, for the first time in the intact circuit, the function and anatomy of aging nigral dopaminergic circuits, we propose to use two powerful technological advances in neuroscience: one for cell-type specific bidirectional control of neuronal activity in vivo with high temporal precision (optogenetics); and one for intact brain circuit mapping and phenotyping, slicing-free (CLARITY). Optogenetics uses microbial opsins, light-sensitive proteins that can be expressed in specified cells via targeting promoters and turned on/off with millisecond speed, thus providing control of cell function with high spatial, temporal, and genetic specificity. Their abilty to control the electrical activity of neural circuits and confer reversible gain and loss of functin of specific neuronal phenotypes allows us to study neural systems and diseases in unprecedented manner. To target subsets of SNc DA neurons we will take advantage of the TH- Cre transgenic lines as well as localized stereotaxic opsin delivery and targeted light application We hypothesize that throughout aging, DA neurons in different SNc tiers have distinct behavioral contributions (Aim 1), which is due to differences in their intrinsic excitability (Aim ) and changes in synaptic inputs (Aim 3). This proposal combines powerful complementary techniques (optogenetics, electrophysiology, and neuroanatomy by CLARITY) to advance our understanding of dopaminergic function and contribution to behavior throughout aging by performing studies in the intact circuit. The PI has been involved in the development of both techniques and our laboratory is ideally positioned to apply these techniques to the aging brain with a focus on the DA system. A better understanding of the properties of DA neurons in the aging SNc can aid in identifying circuit targets and/or behavioral/nutritional methods to delay/reverse age-related alterations in these neurons and in motor functions.

描述（由申请人提供）：在衰老过程中，运动功能下降，精细、快速的运动和协调能力出现缺陷。实验研究将年龄依赖性运动缺陷与多巴胺能 (DA) 通路的故障联系起来，该通路起源于黑质致密部 (SNc)。然而，我们不知道体内不同层黑质神经元的 DA 神经元活性在整个衰老过程中如何变化，什么类型的活性变化先于神经变性，这些活性变化如何影响行为，以及恢复扰动的活动是否可以延缓神经变性和/或行为缺陷。为了首次在完整的回路中表征老化黑质多巴胺能回路的功能和解剖结构，我们建议使用神经科学中两项强大的技术进步：一个用于以高时间精度对体内神经元活动进行细胞类型特异性双向控制（光遗传学）；一种用于完整脑回路图谱和表型分析，免切片 (CLARITY)。光遗传学使用微生物视蛋白，这是一种光敏蛋白，可以通过靶向启动子在特定细胞中表达，并以毫秒速度打开/关闭，从而以高空间、时间和遗传特异性来控制细胞功能。它们控制神经回路的电活动并赋予特定神经元表型功能的可逆增益和丧失的能力使我们能够以前所未有的方式研究神经系统和疾病。为了靶向 SNc DA 神经元子集，我们将利用 TH-Cre 转基因系以及局部立体定向视蛋白递送和靶向光应用我们假设在整个衰老过程中，不同 SNc 层中的 DA 神经元具有不同的行为贡献（目标 1），这是由于它们内在兴奋性（目标）的差异和突触输入的变化（目标 3）造成的。 该提案结合了强大的互补技术（CLARITY 的光遗传学、电生理学和神经解剖学），通过在完整的回路中进行研究，增进我们对多巴胺能功能及其对整个衰老过程中行为的贡献的理解。 PI 参与了这两项技术的开发，我们的实验室非常适合将这些技术应用于衰老的大脑，重点是 DA 系统。更好地了解衰老 SNc 中 DA 神经元的特性有助于识别回路目标和/或行为/营养方法，以延迟/逆转这些神经元和运动功能中与年龄相关的改变。