Synaptic Remodeling and Thyroid Hormones

本项目的主要目标是阐明甲状腺激素 调节脊椎动物神经肌肉接头处的神经肌肉传递。拟议的研究将 解决了一系列关于甲状腺激素（TH）作用的基本问题， 哺乳动物神经肌肉接头（NMJ）。TH对哺乳动物神经元突触前和突触后的作用 终板将被表征。提出了以下三个目标： 目标1。工作假设是TH控制基底微终板电流（MEPC）频率。 在子目标1a中，我们建议描述TH对自发神经递质的急性作用 从哺乳动物NMJ的突触前元件释放。子目标1b旨在 表征参与TH的非转录作用的分子机制。 目标二。我们认为TH水平的改变引起自发动物的变化， 运动，这可以通过外周TH的作用来解释。我们将研究TH水平的变化 产生表型修饰（即，在自发运动，饲养等）短期和长期 甲状腺功能减退和亢进小鼠。此外，我们将这些表型修饰与结构修饰相关联。 使用共聚焦显微镜评估NMJ元件的变化。 目标3：我们推测TH可以直接与突触后乙酰胆碱受体（AChR）相互作用 频道我们计划直接评估这种相互作用，评估肌肉中AChR通道的活性 使用外向贴片和快速灌注从对照、甲状腺功能低下和甲状腺功能亢进小鼠中分离纤维 方法论 这些研究将我们先前的工作扩展到第二阶段，在该阶段中开发了各种方法 在过去的两年中，将被应用于定义哺乳动物中TH效应的生理学方面 NMJ数以百万计的美国人（近2%的人口）受到甲状腺功能障碍的影响。有一个 我们目前对THs在神经系统中作用的基本机制的理解之间的差距 系统和TH已知提供的有益效果。

The primary goal of this project is to elucidate the molecular mechanisms by which thyroid hormones regulate the neuromuscular transmission at the vertebrate neuromuscular junction. The proposed studies will address a series of fundamental questions regarding the action of Thyroid hormones (THs) in the mammalian neuromuscular junction (NMJ). The pre- and post-synaptic effects of THs on the mammalian endplate will be characterized. The following 3 aims are proposed: Aim 1. The working hypothesis is that THs control the basal miniature endplate current (MEPC) frequency. In sub-aim 1a, we propose to characterize the acute action of THs on the spontaneous neurotransmitter release from the presynaptic element of the mammalian NMJ. Sub-aim1b, have been designed to characterize the molecular mechanism involved in the non-transcriptional action of THs. Aim 2. We propose that the modification of THs levels cause changes in the spontaneous animal locomotion, which can be explained by peripheral THs' action. We will study how alterations in THs levels produce phenotype modifications (i.e., in spontaneous locomotion, rearing, etc.) in short-term and long-term hypo- and hyperthyroid mice. Furthermore, we will correlate these phenotype modifications with structural variation in the NMJ elements evaluated using confocal microscopy. Aim 3. We hypothesize that THs could interact directly with the postsvnaptic acetvlcholine receptor (AChR) channel. We plan to directly assess this interaction evaluating the activity of the AChR channel in muscle fibers dissociate from Control, hypo- and hyper-thyroid mice using outside-out patches and fast perfusion methodology. These studies extend our previous work to a second phase, in which a variety of approaches developed during the last two years will be applied to define physiological aspects of the effects of THs in mammalian NMJ. Millions of Americans (near 2% of the population) are affected by thyroid dysfunction. There is a disparity between our current understandings of the basic mechanism underlying THs action in the nervous system and the beneficial effects that THs are known to provide.