CELLULAR PHYSIOLOGY OF CORTICAL DEVELOPMENT

描述：拟议的研究涉及以下基本机制： 中枢神经系统（CNS）期间的选择性突触形成 发展 他们专注于单个已识别突触的形成 在大鼠海马，从苔藓纤维到 CA 3锥体细胞。 两个互补的实验系统， 将使用新生大鼠：（1）海马切片，和（2）齿状- 海马细胞共培养。 实验将采用共焦 细胞结构变化的延时分析，功能成像 测量和电生理学，辅以回顾性 细胞学来识别和表征新生突触。 三大 将继续提出下列问题： 1.未来的突触伴侣--一个苔藓 纤维和一个树突--带来了最初的突触形成 联系人？ 树突状丝状伪足在 突触发生 传入轴突诱导丝状伪足的延伸吗？ 突触发生的接触必须发生在专门的区域，如领导 生长锥或轴突或树枝状丝状伪足的尖端？ 如何 是轴突生长和突触形成事件精心安排， 周期性突触静脉曲张 2. 最初的接触点是如何成熟为最终的突触的？ 一种新的荧光成像突触囊泡回收方法， 电生理学、钙成像和回顾性免疫组织化学， 电子显微镜将被用来分析变化的顺序 在分子结构和功能状态， 最初的接触和完全分化的突触。 3. 初始接触或成熟过程是否受 电活动？ 在对发育的基线分析后， 在前面段落中定义的过程中，实验将被 进行检测的影响，电活动的每一个这些 流程. 通过提供有关细胞基础的新信息， 中枢神经系统突触形成的分子机制，这些研究可能提供 对发育障碍的新见解，如神经分娩 缺陷，学习缺陷和智力迟钝，并建议 治疗中风、中枢神经系统创伤 和退化性疾病如帕金森氏症和阿尔茨海默氏症。 在 此外，由于苔藓纤维发芽异常， 几种癫痫发作疾病，拟议的研究可能会产生结果 立即适用于癫痫。

DESCRIPTION: The proposed studies address basic mechanisms of selective synapse formation during central nervous system (CNS) development. They focus on the formation of a single identified synapse in the rat hippocampus, the en passant synapse from mossy fiber to CA3 pyramidal cell. Two complementary experimental systems from neonatal rat will be used: (1) a hippocampal slice, and (2) dentate- hippocampal cell co-cultures. The experiments will employ confocal time-lapse analysis of cytoarchitectural changes, functional imaging measurements and electrophysiology, supplemented by retrospective cytologies to identify and characterize nascent synapses. Three major questions will be pursued: 1. What motions of the prospective synaptic partners -- one mossy fiber and one dendrite -- bring about the initial synaptogenic contact? What is the role of the dendritic filopodium in synaptogenesis? Do afferent axons induce the extension of filopodia? Must synaptogenic contacts occur at specialized regions such as leading growth cones or the tips of axonal or dendritic filopodia? How are axon growth and synapse formation events orchestrated to form the periodic en passant synaptic varicosities? 2. How does the initial contact site mature into a definitive synapse? A new fluorescence method for imaging synaptic vesicle recycling, electrophysiology, Ca imaging and retrospective immunohistochemistry and electron microscopy will be used to analyze the sequence of changes in molecular architecture and functional status that intervene between the initial contact and the fully differentiated synapse. 3. Are initial contact or maturation processes influenced by electrical activity? After baseline analyses of the developmental processes defined in the preceding paragraphs, experiments will be carried out to detect effects of electrical activity of each of those processes. By providing new information about the basis of cellular and molecular mechanisms of CNS synapse formation, these studies may offer new insights into developmental disorders such as neurological birth defects, learning deficits, and mental retardation, and suggest therapies to combat the neural deficits produced by stroke, CNS trauma and degenerative diseases such as Parkinson's and Alzheimer's. In addition, since abnormal mossy fiber sprouting is implicated in several seizure disorders, the proposed research could produce results immediately applicable to epilepsy.