Synaptic & intrinsic motoneuron excitability in ALS excitotoxicity

突触

• 批准号: 7591242
• 负责人: Jenna E Koschnitzky
• 金额: $ 3.15万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7591242
• 关键词: Adolescent; Adult; Alanine; Amino Acids; Amyotrophic Lateral Sclerosis; Animal Model; Bathing; Birth; Buffers; Calcium; Cells; Cessation of life; Characteristics; Chronic; Development; Disease; Effectiveness; Embryo; FDA approved; Familial Amyotrophic Lateral Sclerosis; Future; Genes; Glutamates; Glycine; Human; In Vitro; Ion Channel; Lead; Life; Maintenance; Mediating; Modeling; Motor Neurons; Mus; Mutate; Mutation; Napping; Neonatal; Neurodegenerative Disorders; Neurons; Paralysed; Patients; Pharmaceutical Preparations; Play; Preparation; Property; Relative (related person); Riluzole; Role; Route; Serum; Slice; Sodium; Spinal Cord; Superoxide Dismutase; Symptoms; Synapses; Therapeutic; Time; Up-Regulation; drug development; excitotoxicity; gamma-Aminobutyric Acid; mouse model; novel; patch clamp; presynaptic

DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is an adult onset neurodegenerative disease which specifically targets motoneurons. In 20% of familial ALS (fALS) cases, there is a specific mutation in superoxide dismutase (SOD1). Mice with mutated human SOD1, display the same pathological and phenotypical symptoms in human ALS patients and are therefore widely used as an animal model of fALS. However, the role SOD1 plays in determining motoneuron death remains unclear. A leading hypothesis is that excitotoxicity caused by an overload of calcium into the cell due to motoneuron hyperexcitability causes selective motoneuron death because motoneurons have a low capacity to buffer calcium. This proposal aims to determine the relative contribution of changes in intrinsic and synaptic motoneuron excitability between wild type and SOD1 motoneurons. Furthermore, the effect of Riluzole, the only FDA approved drug for ALS, on both intrinsic and synaptic motoneuron excitability will also be assessed. The aims of this proposal will be accomplished through the use of embryonic cultured motoneurons, neonatal spinal cord slices, and a new in vitro sacral cord preparation. The use of these preparations will allow an efficient and complete characterization of motoneuron excitability between wild type and SOD1 mice. The in vitro sacral cord preparation allows intrinsic and synaptic motoneuron excitability to be assessed through intracellular recordings at time points throughout development and adulthood. It also enables us to administer Riluzole at therapeutic levels and in multiple time courses to extensively characterize the effects of Riluzole over time. The neonatal spinal cord slice preparation allows intrinsic versus synaptic motoneuron excitability to be assessed using direct bath application of drugs to inhibit specific ion channels using a whole cell patch clamp configuration. Also, the direct and immediate effects of Riluzole on motoneurons can be determined. The embryonic cultured motoneurons provide a window into motoneuron abnormalities present before birth and also give us a preparation where no synaptic inputs are present. In this preparation the effects of Riluzole administered over multiple time courses on the intrinsic properties of motoneurons can be isolated. The cause(s) of motoneuron degeneration in ALS needs to be determined in order to develop novel drugs treatments and understanding differences or changes in motoneuron function will lead to specific targets for these future drugs. Furthermore, early detectable changes in motoneuron function may enable the use of pre-emptive therapies that can significantly delay or even arrest the development of the disease.

描述（由申请人提供）：肌萎缩侧索硬化症（ALS）是一种成人发病的神经退行性疾病，专门针对运动神经元。 20% 的家族性 ALS (fALS) 病例中，超氧化物歧化酶 (SOD1) 存在特定突变。携带人类 SOD1 突变的小鼠表现出与人类 ALS 患者相同的病理和表型症状，因此被广泛用作 fALS 的动物模型。然而，SOD1 在决定运动神经元死亡中所起的作用仍不清楚。一个主要的假设是，由于运动神经元过度兴奋，导致细胞内钙超载而引起的兴奋性毒性会导致选择性运动神经元死亡，因为运动神经元缓冲钙的能力较低。该提案旨在确定野生型和 SOD1 运动神经元之间内在和突触运动神经元兴奋性变化的相对贡献。此外，利鲁唑（FDA 唯一批准的治疗 ALS 的药物）对内在运动神经元和突触运动神经元兴奋性的影响也将得到评估。该提案的目标将通过使用胚胎培养的运动神经元、新生儿脊髓切片和新的体外骶索制剂来实现。使用这些制剂将能够有效、完整地表征野生型和 SOD1 小鼠之间的运动神经元兴奋性。体外骶索制剂允许通过整个发育和成年期各时间点的细胞内记录来评估内在和突触运动神经元兴奋性。它还使我们能够以治疗水平和多个时间疗程施用利鲁唑，以广泛表征利鲁唑随时间的影响。新生儿脊髓切片制备允许使用直接药物浴应用来评估内在与突触运动神经元兴奋性，以使用全细胞膜片钳配置抑制特定离子通道。此外，还可以确定利鲁唑对运动神经元的直接和即时影响。胚胎培养的运动神经元为了解出生前存在的运动神经元异常提供了一个窗口，也为我们提供了不存在突触输入的准备。在该制剂中，可以分离出多次给药的利鲁唑对运动神经元固有特性的影响。需要确定 ALS 运动神经元变性的原因，以便开发新的药物治疗方法，并且了解运动神经元功能的差异或变化将导致这些未来药物的特定靶点。此外，早期可检测到的运动神经元功能的变化可能使我们能够使用先发制人的疗法，从而显着延迟甚至阻止疾病的发展。