Non-invasive Chemical Genetic Control of Neuronal Activity

神经元活动的非侵入性化学遗传控制

• 批准号: 7684412
• 负责人: MICHAEL D EHLERS
• 金额: $ 39万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7684412
• 关键词: Action Potentials; Acute; Afferent Neurons; Agonist; Animals; Area; Autistic Disorder; Behavior; Behavioral; Blood - brain barrier anatomy; Brain; Cannulas; Capsaicin; Cells; Charge; Data; Development; Dopamine; Dose; Engineering; Epilepsy; FOS gene; Fluorescent Dyes; Gated Ion Channel; Genetic; Glutamates; Goals; Implant; Infusion procedures; Injection of therapeutic agent; Knock-in Mouse; Laboratories; Lidocaine; Ligands; Maps; Membrane; Memory; Mental disorders; Metabolic; Metabolism; Methods; Microdialysis; Modeling; Monitor; Mus; Neurologic; Neurons; Neurosciences; Nociception; Operative Surgical Procedures; Optics; Pan Genus; Peripheral; Pharmaceutical Preparations; Physiological; Population; Public Health; Purkinje Cells; Reading; Regulation; Research; Resiniferatoxin; Response Latencies; Route; Schizophrenia; Slice; Sodium Channel; Sodium Channel Blockers; Specificity; Staining method; Stains; Stereotyped Behavior; System; TRPV1 gene; Techniques; Technology; Testing; Therapeutic; Time; Work; addiction; awake; base; behavior influence; brain cell; cell type; chemical genetics; depression; direct application; dopaminergic neuron; implantation; in vivo; interest; light gated; mouse model; neural circuit; neural stimulation; new technology; novel; programs; public health relevance; public health research; receptor; relating to nervous system; research study; response; sensory stimulus; small molecule; technology development

DESCRIPTION (provided by applicant): Mapping functional circuits is a major goal for both cellular and systems neuroscience. Current approaches for mapping neural circuits are limited by the lack of technologies for evoking cell-specific neural activity. Available methods of neural stimulation rely on either local application of undiscriminating fields of electrical currents, glutamate uncaging, or the presentation of artificial sensory stimuli. Although recent use of light- gated ion channels has provided optical control of neuronal activity on rapid time scales, such approaches are limited by the requirement for direct optical access to neuronal populations of interest, and are not currently suitable for activating large brain areas or disperse neuronal populations. A transformative technology for neuroscience would be non-invasive control over neural activity in genetically defined populations of neurons in the mammalian brain. Such a goal requires combining genetic sensitization of neuronal subsets with a means to manipulate their electrical activity remotely without surgery or intracranial implants. To create such a technology, my laboratory has initiated a program of in vivo chemical genetic and physiological studies to engineer a mouse model suitable for precise non-invasive manipulation of neural activity in genetically defined populations of neurons in vivo. We have developed a conditional mouse model that sensitizes genetically defined neurons to an artificial ligand (capsaicin) by cell type-specific expression of a heterologous receptor (TRPV1). We have found that application of capsaicin to neurons expressing TRPV1 induces strong inward currents, triggers robust firing of action potentials, and activates stereotyped behaviors. Taking advantage of these preliminary data, and the extensive pharmacological and biophysical characterization of TRPV1, we propose to extend and modify this model to enable peripheral administration of agonists for central activation of defined neuronal subsets. Moreover, because the large TRPV1 channel pore is permeable to small molecules, including the membrane-impermeant sodium channel blocker QX-314, we propose to test this novel mouse model to enable both activation and inhibition of neuronal activity. This work will allow for the development of a novel in vivo technology for chemical genetic regulation of neuronal activity that is (1) orthogonal to optical and optogenetic strategies, (2) based on the only current Cre/lox-based model for neuronal activation, (3) may allow for fully non-invasive CNS activation by drug injection, and (4) may enable targeted small molecule delivery to defined neuronal subsets. PUBLIC HEALTH RELEVANCE: The proposed research will develop a novel technology for non-invasive control over electrical activity in genetically defined populations of brain cells. Abnormal electrical activity in the brain contributes to epilepsy, memory decline, depression, autism, schizophrenia, and addiction. By developing a crucial new technology for targeted manipulation of brain cell activity and metabolism, the proposed research will define novel brain circuits and therapeutic strategies for treating these devastating neurological and psychiatric disorders, which currently have a profound negative impact on public health.

描述(由申请人提供)：绘制功能电路图是细胞和系统神经科学的主要目标。目前映射神经回路的方法受到缺乏唤起细胞特异性神经活动的技术的限制。现有的神经刺激方法要么依赖于局部施加无区别的电流，要么依赖于谷氨酸去除，要么依赖于人工感官刺激。虽然最近使用光门离子通道在快速时间尺度上提供了对神经元活动的光学控制，但这种方法受到直接光学访问感兴趣的神经元群体的要求的限制，目前不适合于激活大片大脑区域或分散的神经元群体。神经科学的一项变革性技术将是对哺乳动物大脑中由基因定义的神经元群体中的神经活动进行非侵入性控制。这样的目标需要将神经元亚群的遗传敏感化与一种无需手术或颅内植入即可远程操纵其电活动的手段结合起来。为了创造这样的技术，我的实验室启动了一个体内化学遗传和生理研究计划，以设计一种小鼠模型，适合对体内遗传定义的神经元群体中的神经活动进行精确的非侵入性操作。我们开发了一种条件性小鼠模型，通过异源受体(TRPV1)的细胞类型特异性表达，使遗传定义的神经元对人工配体(辣椒素)敏感。我们发现，将辣椒素应用于表达TRPV1的神经元，可以诱导强烈的内向电流，触发动作电位的强健激发，并激活刻板印象的行为。利用这些初步数据，以及TRPV1广泛的药理学和生物物理特性，我们建议扩展和修改这一模型，以使外周给药能够对定义的神经元亚群进行中枢激活。此外，由于大的TRPV1通道孔对小分子具有通透性，包括膜无关的钠通道阻滞剂QX-314，我们建议测试这一新的小鼠模型，使其能够激活和抑制神经元活动。这项工作将有助于开发一种新的体内神经活动化学遗传调节技术，该技术(1)与光学和光遗传策略正交，(2)基于当前唯一的基于Cre/LOX的神经元激活模型，(3)可以通过注射药物完全非侵入性地激活中枢神经系统，以及(4)可以将小分子靶向传递到定义的神经元亚群。公共卫生相关性：这项拟议的研究将开发一种新技术，用于对遗传定义的脑细胞群体中的电活动进行非侵入性控制。大脑中异常的电活动会导致癫痫、记忆力减退、抑郁、自闭症、精神分裂症和成瘾。通过开发一种关键的新技术来定向操纵脑细胞活动和新陈代谢，拟议的研究将定义新的大脑电路和治疗策略，用于治疗这些破坏性的神经和精神疾病，这些疾病目前对公共健康有深远的负面影响。