CHEMICAL TRANSDUCTION & MODULATION OF CHANNEL CURRENTS

化学传导

• 批准号: 3408066
• 负责人: ROBERT J O'CONNELL
• 金额: $ 22.79万
• 依托单位: WORCESTER FOUNDATION FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-09-25 至 1990-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3408066
• 关键词: action potentials; biochemistry; biophysics; chemoreceptors; dendrites; electron microscopy; electrophysiology; medial olfactory area; neural information processing; olfactions; pheromone; phospholipids; radioassay; sensory feedback; single cell analysis

The incessant flow of chemical signals between and among the individual neural elements of the brain is widely acknowledged to be an essential determinant of higher neural function. Therefore the physiological mechanisms which underlie the ability of primary olfactory receptor neurons to detect, transduce and process chemical signals must provide a good model for these processes elsewhere in the brain. Individual olfactory receptor neurons respond to multiple chemical stimuli and differ dramatically in the particular array of effective odorants and in the relative amounts of each required to elicit a significant change in action potential production. In receptor neurons, most receptor sites, second messenger systems and single current channels are thought to be integral plasma membrane proteins. Thus, the complexity seen in olfactory receptor neurons can be ascribed to differences in the kind, number, distribution, activation and interaction among these individual proteins. Activation of receptor sites is presumed to stimulate or modulate in some way, perhaps through a second messenger mechanism, various ionic currents which flow through the integral membrane channels. These brief individual currents, in concert, ultimately result in sufficient transmembrane current flow to generate a propagated action potential. In these experiments fragments of insect olfactory receptor neuron dendrites will be reconstituted in phospholipid bilayers on the tips of patch electrodes in order to explore the biophysics of olfactory transduction, signal amplification and current flow. The questions to be asked include: 1) Does an individual odor interact with more than one kind of receptor site? 2) Are there different kinds of receptor sites on single olfactory receptor neurons? 3) If there are, how many kinds are there and how do they differ in their individual binding properties? 4) Does the activation of one type of receptor site influence the activation of another? 5) How are these receptor sites coupled to the activation of single channel currents? 6) Do effective odors modulate single channel currents directly, or indirectly through a second messenger system? 7) If second messenger systems are involved, how are they modulated and regulated? 8) Are particular types of receptor sites always associated with a particular type of channel or second messenger system? 9) How many different types of individual channel currents are there? 10) How do channels vary in their ionic requirements and voltage dependence? Answers to these questions will aid in our understanding of brain function.

化学信号的不断流动， 大脑的单个神经元被广泛认为 是高级神经功能的重要决定因素 因此 生理机制的基础能力， 初级嗅觉受体神经元检测，识别和 过程化学信号必须为这些提供良好的模型 在大脑的其他地方。 个体嗅觉感受器 神经元对多种化学刺激有反应， 显著地在特定的有效气味剂阵列中， 每种物质的相对量， 动作电位产生的变化。 在受体神经元中， 受体位点、第二信使系统和单电流 通道被认为是完整的质膜蛋白。 因此，在嗅觉受体神经元中看到的复杂性可以是 归因于种类、数量、分布、 这些蛋白质之间的相互作用。 受体位点的激活被认为是刺激或调节 在某种程度上，也许通过第二信使机制， 流过整体膜的各种离子电流 渠道 这些短暂的个体电流，最终 导致足够的跨膜电流流动， 传播动作电位 在这些实验中， 昆虫嗅觉受体神经元树突将在 磷脂双层的贴片电极的尖端，以便 探索嗅觉传导的生物物理学，信号， 放大和电流。 要问的问题 包括：1）一种气味是否与多种气味相互作用？ 一种受体部位 2)是否有不同种类的受体 单个嗅觉受体神经元上的位点？ 3)如果有的话， 有很多种，它们在个体上有什么不同 绑定属性？ 4)一种受体的激活 网站影响另一个激活？ 5)这些是怎么 受体位点偶联激活单通道 电流？ 6)有效的气味能调节单通道电流吗 直接或间接通过第二信使系统？ 7)如果 第二信使系统参与其中，它们是如何调节的 和监管？ 8)特定类型的受体位点是否总是 与特定类型的通道或第二信使相关联 系统中？ 9)有多少种不同类型的个人频道 电流在？ 10)离子通道是如何变化的 要求和电压依赖性？ 回答这些 这些问题将有助于我们了解大脑的功能。