Generation of mice to selectively mark a subset of spinal interneurons

产生选择性标记脊髓中间神经元子集的小鼠

• 批准号: 9374839
• 负责人: George Z Mentis
• 金额: $ 8万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9374839
• 关键词: Acetylcholine; Antibodies; Aspartate; Axon; Behavior; Cell Nucleus; Cells; Cerebellum; Characteristics; Cholinergic Receptors; Complex; Data; Exhibits; Fluorescent in Situ Hybridization; Funding; Generations; Genes; Genetic Markers; Genetic Recombination; Glutamates; Goals; Grant; Halorhodopsins; Immunohistochemistry; Individual; Injectable; Interneurons; Knock-in Mouse; Label; Limb structure; Locomotion; Mediator of activation protein; Microarray Analysis; Modernization; Motor; Motor Activity; Motor Neurons; Motor output; Movement; Mus; Muscle; Neonatal; Neurons; Neurosciences; Neurotransmitters; Output; Periodicity; Peripheral; Play; Population; Regulation; Renshaw Cell; Reporter; Reporting; Research Project Grants; Role; Sensitivity and Specificity; Specificity; Spinal; Spinal Cord; Spinocerebellar Tracts; Synapses; Testing; Tracer; Validation; Ventral Roots; ZFHX3 gene; base; behavior test; central pattern generator; design; experimental study; insight; intersectionality; neuronal circuitry; novel; selective expression

Project Summary A major goal of modern Neuroscience is to understand the neuronal basis of behavior. Locomotion is a behavior generated in the spinal cord by complex neuronal circuits. It is defined as precise, coordinated and alternating activity between opposing limbs as well as between antagonistic muscles of the same limb. Furthermore, locomotor behavior is attractive for experimental study because it can be easily accessed, defined, and quantified. A network of interneurons, known as the central pattern generator (CPG), is thought to be responsible for the genesis of rhythmic activity. CPG neurons activate motor neurons which in turn activate peripheral muscles resulting in movement. Motor neurons also possess axon collaterals which target exclusively a class of inhibitory interneurons, known as Renshaw cells. Our recent studies have challenged the traditional idea that motor neurons are simply the motor output from the spinal cord. Stimulation of motor neuron axons in neonatal mice can trigger locomotor activity in the presence of cholinergic receptor antagonists. This suggests that acetylcholine released by motor neuron axon collaterals is not required for rhythmogenesis. Furthermore, we discovered that neonatal motor neurons release a second fast excitatory neurotransmitter from their axon collaterals (glutamate or aspartate) in addition to acetylcholine. The mechanisms of how stimulation of motor axons can trigger locomotor-like activity in neonatal spinal cords are not understood. The identification of neurons and their connectivity that participate in the locomotor CPG is critically needed for the elucidation of mechanisms involved in locomotor activity and would therefore represent a fundamental advance in the field. In this proposal, we provide strong preliminary evidence that a novel class of excitatory interneurons is a critical component in a ventral spinal cord circuit and it may be involved in the locomotor central pattern generator. We aim to generate novel mouse lines that express select genes in this class of spinal interneurons to test our main hypothesis, that these spinal interneurons play an active role in the generation of locomotor activity. In Aim 1, we will generate two knock-in mouse lines to be used as an intersection approach in order to label selectively a class of spinal interneurons. In Aim 2, we will validate the selectivity and efficiency of both mouse lines individually as well as when they are crossed amongst them. In summary, this two-year research project describes a comprehensive design of generation of knock-in mouse lines that have the potential to identify a novel class of excitatory interneurons as a key neuronal player in the rhythmogenesis of locomotor activity.

项目概要 现代神经科学的一个主要目标是了解行为的神经元基础。运动是一个 由复杂的神经元回路在脊髓中产生的行为。它被定义为精确、协调和 对立肢体之间以及同一肢体的拮抗肌之间的交替活动。 此外，运动行为对实验研究很有吸引力，因为它很容易获得， 定义并量化。中间神经元网络，称为中央模式生成器（CPG），被认为 负责节律活动的发生。 CPG 神经元激活运动神经元，进而 激活周围肌肉从而产生运动。运动神经元还拥有轴突侧枝，其目标是 完全是一类抑制性中间神经元，称为伦肖细胞。我们最近的研究挑战了 传统观念认为运动神经元只是脊髓的运动输出。运动刺激 新生小鼠的神经元轴突可以在胆碱能受体存在的情况下触发运动活动 对手。这表明运动神经元轴突侧枝释放的乙酰胆碱不是 节律发生。此外，我们发现新生儿运动神经元释放第二个快速兴奋性神经元 除了乙酰胆碱之外，还来自轴突侧支的神经递质（谷氨酸或天冬氨酸）。这 刺激运动轴突如何触发新生儿脊髓的运动样活动的机制是 不明白。参与运动 CPG 的神经元及其连接的识别是 阐明参与运动活动的机制至关重要，因此代表 该领域的根本性进步。在这个提案中，我们提供了强有力的初步证据，表明一个新颖的类别 兴奋性中间神经元是腹侧脊髓回路的关键组成部分，它可能参与 运动中枢模式发生器。我们的目标是产生表达该基因的新型小鼠品系 类脊髓中间神经元来检验我们的主要假设，即这些脊髓中间神经元在 运动活动的产生。 在目标 1 中，我们将生成两条敲入鼠标线，用作交叉方法以标记 选择性地一类脊髓中间神经元。在目标 2 中，我们将验证两种鼠标的选择性和效率 单独的线以及线之间交叉时。综上所述，这个为期两年的研究项目 描述了生成敲入小鼠品系的综合设计，该小鼠品系有可能识别 新型兴奋性中间神经元作为运动活动节律发生中的关键神经元参与者。