DEVELOPMENT OF SENSORY--MOTONEURON CONTACTS

感觉发育--运动神经元接触

• 批准号: 3407715
• 负责人: Lea Ziskind-Conhaim
• 金额: $ 7.56万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-07-01 至 1989-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3407715
• 关键词: afferent nerve; cell cell interaction; cell differentiation; central nervous system; dorsal root; electron microscopy; electrophysiology; embryo /fetus; gene expression; histology; innervation; motor neurons; nervous system regeneration; neural information processing; neuromuscular function; neuropharmacology; organ culture; peripheral nervous system; spinal reflex; stretch receptors; synapses

The objectives are to study the inductive relationship between developing central and peripheral synapses, and the influence of these synapses on development changes in motoneuron properties. To ensure specific and long-term interaction between cells, differentiation of synapses is directed by gene expression as well as by influential signals passing in both directions across the synapse. Detailed information has accumulated describing the function of sensory-motor connection in adult vertebrates, but little is known about their development. Most knowledge comes from studies of developing central synapses in invertebrates, and non-mammalian vertebrates such as tadpole and chick. I will study the electrical and pharmacological properties of immature motoneurons in rat embryos, and investigate the roles of developing primary afferent-motoneruon contacts and peripheral nerve-muscle interactions on these properties. I shall study pattern and time course of development of spinal reflexes and the initial specificity of afferent-motoneuron contacts. Studies will be carried out in vitro, using isolated segments of thoracic spinal cord with or without their adjacent intercostal muscles. The small size of the embryonic spinal cord allows adequate penetration of oxygen and nutrients into the tissue. The advantages of using spinal cord-intercostal muscle explants are: 1) motoneurons are cultured in continuity with the muscles they normally innervate in vivo, and 2) we have previously described the chronology changes that occur during development of intercostal nerve-muscle contacts in vivo and in organ culture, and thus will be able to correlate these changes with the differentiation of motoneurons that innervate them. Maintaining these explants in the controlled environment of organ culture is valuable for isolating signals that influence motoneuron properties and the formation of central neuronal interactions. To broaden our knowledge about the way functional neuronal circuits develop, we must extend our information about the mechanisms involved in specificity of synapses during development. Such an understanding may give insight into mechanisms of long-term interactions between cells and reasons for their inability to re-establish these interaction following lesions in the central nervous system.

目的是研究发展之间的归纳关系 中央和外围突触，这些突触的影响 运动神经元特性的发展变化。 确保具体并 细胞之间的长期相互作用，突触的分化是 由基因表达以及通过传递的影响信号指导 两个方向穿过突触。 详细信息已积累 描述成年脊椎动物中感觉运动连接的功能， 但是对他们的发展知之甚少。 大多数知识来自 研究无脊椎动物和非哺乳动物的中央突触的研究 脊椎动物，例如t和小鸡。 我将研究电气和 大鼠胚胎中未成熟运动神经元的药理特性， 研究开发主要传入 - 摩托龙触点的作用 以及这些特性上的周围神经肌肉相互作用。 我将 脊柱反射的研究模式和时间过程 传入 - 单神经元触点的初始特异性。 研究将在体外使用胸部分离的段进行体外进行 脊髓有或没有邻近的肋间肌肉。 小 胚胎脊髓的尺寸允许氧气渗透和 营养成组织。 使用脊髓间隔的优点 肌肉外植体是：1）运动神经元与 它们通常在体内支配肌肉，2）我们以前有 描述了在开发过程中发生的年表变化 体内和器官培养中的肋间神经肌肉接触，因此 将能够将这些变化与分化 支配它们的运动神经元。 在 器官文化的控制环境对于隔离信号很有价值 这会影响运动神经元特性和中央神经元的形成 互动。 扩大我们对功能性神经元电路方式的认识 开发，我们必须扩展有关涉及机制的信息 发育过程中突触的特异性。 这样的理解可能会给 深入了解细胞与原因之间长期相互作用的机制 因为他们无法在病变后重新建立这些相互作用 中枢神经系统。