IONIC CURRENTS OF ISOLATED SPINAL NEURONS

孤立脊髓神经元的离子电流

• 批准号: 3430207
• 负责人: JAMES T BUCHANAN
• 金额: $ 6.6万
• 依托单位: MARQUETTE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-30 至 1994-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3430207
• 关键词: Agnatha; GABA receptor; NMDA receptors; action potentials; alternatives to animals in research; calcium flux; electrophysiology; glycine receptors; interneurons; membrane potentials; microcapsule; microelectrodes; motor neurons; neural conduction; neural transmission; neurochemistry; neurons; neuropharmacology; phase contrast microscopy; potassium channel; serotonin; single cell analysis; spinal cord; synapses; voltage /patch clamp

The work proposed in this application is part of an on-going study of how the vertebrate nervous system generates and controls locomotor activity. The present study will seek to broaden our understanding of some of the ionic currents underlying single-cell behavior. In particular this study will record the ionic currents of single, isolated neurons from the spinal cord of a primitive vertebrate, the lamprey. The specific aims in studying these cells are to 1) investigate the mechanisms of presynaptic inhibition in sensory neurons and spinal axons, 2) determine whether the neurotransmitter serotonin alters calcium currents in branched neurons as a mechanism for reducing the late after-spike-hyperpolarization, 3) address the controversy regarding whether or not there are distinct glycine and gamma-aminobutyric acid receptors in the lamprey nervous system, and 4) determine whether N-methyl-D-aspartate (NMDA)-induced, tetrodotoxin-resistant membrane potential oscillations can occur in isolated neurons and determine the nature of their repolarizing current. The cells will be mechanically dissociated after a collagenase and pro- tease incubation. Different classes of lamprey spinal neurons will be identified morphologically or by pre-labelling with retrograde, fluorescent tracers In vivo. Ionic currents will be recorded in whole-cell voltage-clamp mode with patch electrodes, and individual ionic currents will be isolated by pharmacological means and by their characteristic voltage and kinetic properties. Drugs will be applied by bath perfusion to examine their effects on the isolated ionic currents. These studies will contribute to our basic understanding regarding the function of the spinal cord. Such understanding is important in the development of therapeutic measures to treat spinal cord injury and disease.

本申请中提出的工作是一项正在进行的研究的一部分 脊椎动物神经系统产生并控制运动活动。 本研究将寻求扩大我们对某些问题的理解 单细胞行为的离子电流。 特别是这项研究 将记录来自 原始脊椎动物七鳃鳗的脊髓。 具体目标在 研究这些细胞的目的是 1）研究突触前的机制 感觉神经元和脊髓轴突的抑制，2) 确定是否 神经递质血清素改变分支神经元中的钙电流 减少后期尖峰后超极化的机制，3) 解决是否有明确的争议 七鳃鳗神经中的甘氨酸和γ-氨基丁酸受体 系统，以及 4) 确定 N-甲基-D-天冬氨酸 (NMDA) 是否诱导， 抗河豚毒素的膜电位振荡可发生在 分离神经元并确定其复极电流的性质。 胶原酶和亲蛋白后，细胞将被机械解离。 挑逗孵化。 不同类别的七鳃鳗脊髓神经元将 形态学上或通过逆行预标记来识别， 体内荧光示踪剂。 离子电流将被记录在 具有贴片电极和单独离子的全细胞电压钳模式 电流将通过药理学手段和它们的隔离 特征电压和动力学特性。 药物将通过 浴灌注以检查它们对隔离离子电流的影响。 这些研究将有助于我们对 脊髓的功能。 这种理解对于 开发治疗脊髓损伤的治疗措施 疾病。