Neuronal plasticity and cerebellar circuitry

神经元可塑性和小脑回路

基本信息

批准号：
7339131
负责人：
NEAL H BARMACK
金额：
$ 30.37万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-08-01 至 2012-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7339131
关键词：
Cells Cerebellar Diseases Cerebellum Class Complex Contralateral Dendrites Depth Fiber Golgi Apparatus Green Fluorescent Proteins Inferior Injection of therapeutic agent Interneurons Ipsilateral Ketamine Label Labyrinth Left Measures Medial Dorsal Nucleus Mediating Messenger RNA Methods MicroRNAs Molecular Mus Neuronal Plasticity Oligonucleotides Olives - dietary Output Pathway interactions Patients Pattern Phase Physiological Physiology Proteins Purkinje Cells RNA Interference Relative (related person)Research Research Personnel Role Side Signal Transduction Speed Stimulus System Techniques Testing Time Viral Vector Xylazine adeno-associated viral vector base cell type gamma-Aminobutyric Acid granule cell in vivo knock-down labyrinthectomy metabotropic glutamate receptor 2 mossy fiber neurobiotin programs promoter receptor research study synthetic enzyme theories uvula vector

项目摘要

DESCRIPTION (provided by applicant): In vivo analysis of cerebellar circuitry has focused almost exclusively on Purkinje cells, identified by their iconic patterns of complex and simple spikes (CSs and SSs). However, views of cerebellar function based exclusively on the physiology of Purkinje cells ignore the role of interneurons and distort the attributes of cerebellar afferent systems. It is universally assumed that SSs are modulated by the activity of the mossy fiber-granule cell-parallel fiber projection to Purkinje cell dendrites. In fact, during natural vestibular stimulation, vestibular primary afferent mossy fiber afferents discharge out of phase with the SSs recorded from nodular Purkinje cells. Consequently, it is unlikely that the cerebellar output signal merely reflects a gain-controlled version of the mossy fiber input signal. We proposed that SS modulation reflects the action of climbing fibers on cerebellar interneurons. We will test specific versions of this hypothesis by recording from identified interneurons. We have three objectives. First, we will record extracellularly from interneurons in the uvula-nodulus of anesthetized mice during natural vestibular stimulation. Interneurons will be labeled juxtacellularly with neurobiotin. The depth and phase of modulation of interneuronal discharge relative to that of Purkinje cell CSs and SSs will indicate which interneurons could modulate SSs. Second, we will study how the modulated activity of interneurons and Purkinje cells is altered by a unilateral labyrinthectomy (UL). Following a UL, the ipsilateral uvula-nodulus is accessible to vestibular information mediated only by climbing fibers whose modulation depends on the contralateral, intact labyrinth. Third, we will also make microlesions in the p-nucleus and dorsomedial cell column (dmcc) in the contralateral inferior olive. This will leave one side of the cerebellum accessible to vestibular information mediated only by vestibular mossy fibers. We will compare the effects of reduced vestibular signaling on interneurons and Purkinje cells. Fourth, we will microinject miRNAs in viral vectors with a cell specific promoter to selectively reduce expression of GABA-A alpha 1 receptors in nodular Purkinje cells. Fifth, we will also use miRNAs to selectively reduce synthesis of GABA in Golgi cells. We will analyze the effects of "knocking down" GABAergic signaling in these two cell types. We will characterize the stimulus-modulated functions of identified interneurons for the first time. We will interfere with cerebellar circuitry at a cellular level and test the role of interneurons in the modulation of SSs. The proposed research will speed application of molecular techniques to the treatment of patients with cerebellar disorders.

描述（由申请人提供）：小脑回路的体内分析几乎完全集中于浦肯野细胞，通过复杂和简单尖峰（CS 和 SS）的标志性模式来识别。然而，完全基于浦肯野细胞生理学的小脑功能观点忽视了中间神经元的作用并扭曲了小脑传入系统的属性。人们普遍认为，SS 是通过苔藓纤维-颗粒细胞-平行纤维投射到浦肯野细胞树突的活性来调节的。事实上，在自然前庭刺激期间，前庭初级传入苔藓纤维传入与结节浦肯野细胞记录的 SS 异相放电。因此，小脑输出信号不太可能仅仅反映苔藓纤维输入信号的增益控制版本。我们提出 SS 调制反映了攀爬纤维对小脑中间神经元的作用。我们将通过记录已识别的中间神经元来测试该假设的特定版本。我们有三个目标。首先，我们将在自然前庭刺激期间记录麻醉小鼠悬雍垂结节中中间神经元的细胞外数据。中间神经元将用神经生物素进行细胞旁标记。相对于浦肯野细胞 CS 和 SS 的中间神经元放电调节的深度和相位将表明哪些中间神经元可以调节 SS。其次，我们将研究单侧迷路切除术 (UL) 如何改变中间神经元和浦肯野细胞的调节活动。 UL 后，同侧悬雍垂结节只能通过攀爬纤维介导的前庭信息，而攀爬纤维的调节取决于对侧完整的迷路。第三，我们还将在对侧下橄榄的 p 核和背内侧细胞柱 (dmcc) 中制造微损伤。这将使小脑的一侧能够接触到仅由前庭苔藓纤维介导的前庭信息。我们将比较前庭信号传导减少对中间神经元和浦肯野细胞的影响。第四，我们将 miRNA 显微注射到具有细胞特异性启动子的病毒载体中，以选择性降低结节性浦肯野细胞中 GABA-A α 1 受体的表达。第五，我们还将利用miRNA选择性地减少高尔基体细胞中GABA的合成。我们将分析“敲低”GABAergic 信号传导对这两种细胞类型的影响。我们将首次描述所识别的中间神经元的刺激调节功能。我们将在细胞水平上干扰小脑回路并测试中间神经元在 SS 调节中的作用。拟议的研究将加速分子技术在治疗小脑疾病患者中的应用。