SODIUM CHANNELS OF DORSAL ROOT GANGLION NEURONS

背根神经节的钠通道

• 批准号: 2259586
• 负责人: MARCO A RIZZO
• 金额: $ 9.48万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-12-01 至 1997-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2259586
• 关键词: animal age group; dorsal root; electrophysiology; ganglions; injury; laboratory rat; neurons; single cell analysis; sodium channel; tissue /cell culture; voltage /patch clamp; voltage gated channel

The overall goal of this proposal is to increase our understanding of the molecular pathophysiology of nerve injury. The proposed studies are designed to reveal a possible molecular mechanism for ectopic impulse generation on the basis of altered Na+ channel expression in the somatic membrane of chronically injured DRG neurons. A modified patch-clamp method for recording macroscopic currents from mammalian neurons will be used. Na+ currents will be characterized in embryonic, neonatal, adult and axotomized adult DRG neurons. The potential library of Na+ channels which can be expressed on DRG somatic membrane will be determined. Specific objectives: (1) To survey Na+ channels in small, medium, and large DRG neurons in adult rats, to differentiate channel subpopulations as they occur in cells of different sensory modality. (2) To reveal changes in Na+ channel populations in somatic membrane of DRG neurons with age. (3) To reveal the regional distribution of Na+ channel subpopulations in a single DRG neuron. (4) To determine changes in somatic membrane Na+ channel properties in response to chronic injury in adult DRG neurons. Methods: Cultured DRG neurons exised from adult, neonatal, and embryonic rat will be used. In experiments on injured neurons, the sciatic nerve will be ligated 19 to 21 days prior to excision of the ipsilateral lumbar DRGs. Macroscopic Na+ currents will be recorded via patch-clamp of whole cells and of fragments of membrane ('blebs') placed in a customized perfusion/dialysis chamber. Pulse protocols, data acquisition, and analysis will be computer controlled. The 'P/4' method will be applied to minimized leak and capacity currents. Na+ channels will be characterized according to sensitivity to block by tetrodotoxin, steady-state activation and inactivation curves, and kinetic properties. Comparisons of Na+ channel properties will be done among cells of different size, age, and among different portions of membrane (somatic, neuritic, axonal). Properties of Na+ channels obtained from somatic membrane of injured adult neurons will be compared with those of healthy adults and neonates to reveal the subpopulation of channels accessed in response to injury.

该提议的总体目标是提高我们对 神经损伤的分子病理生理学。 拟议的研究是 旨在揭示异位脉冲的可能分子机制 根据改变体细胞的Na+通道表达的生成 长期受伤的DRG神经元的膜。 修改后的贴片钳 从哺乳动物神经元记录宏观电流的方法将是 用过的。 Na+电流将在胚胎，新生儿，成人中进行表征 和轴向成年DRG神经元。 NA+通道的潜在库 可以在DRG体细胞膜上表达的。 特定目标：（1）调查小型，中和中的Na+通道 成年大鼠中的大型DRG神经元，以区分通道亚群 当它们发生在不同感觉方式的细胞中。 （2）揭示 DRG神经元体细胞膜中Na+通道种群的变化 随着年龄的增长。 （3）揭示Na+通道的区域分布 单个DRG神经元中的亚群。 （4）确定变化 响应慢性损伤的体细胞膜Na+通道特性 成人DRG神经元。 方法：从成人撤离的培养的DRG神经元， 将使用新生儿和胚胎大鼠。 在受伤的实验中 神经元，坐骨神经将在19至21天之前连接 切除同侧腰椎DRG。 宏观Na+电流将 通过全细胞和膜碎片的斑块钳记录 （'Blebs'）放置在定制的灌注/透析室中。 脉冲 协议，数据采集和分析将受到计算机的控制。 “ P/4”方法将用于最小化泄漏和容量电流。 Na+通道将根据对阻止的敏感性来表征 四毒素，稳态激活和灭活曲线，以及 动力学特性。 将进行NA+通道属性的比较 在不同大小，年龄和不同部分的细胞中 膜（体细胞，神经，轴突）。 Na+通道的特性 将比较从受伤的成年神经元的体膜获得的 与健康的成年人和新生儿的人一起揭示了 响应伤害的通道。