Voltage-dependent ion channels controlling firing patterns of central neurons

电压依赖性离子通道控制中枢神经元的放电模式

• 批准号: 10225152
• 负责人: BRUCE P BEAN
• 金额: $ 16.81万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2021-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10225152
• 关键词: 4-Aminopyridine; Action Potentials; Acute; Ataxia; Behavior; Brain; Calcium Channel; Clinical; Closure by clamp; Data; Disease; Dissection; Drug usage; Electrophysiology (science); Elements; Enhancers; Epilepsy; Experimental Designs; Functional disorder; Goals; Grant; Hippocampus (Brain); Investigation; Ion Channel; Kinetics; Knowledge; Lead; Link; Midbrain structure; Molecular Target; Nervous System Physiology; Neurons; Neurosciences Research; Pattern; Pharmaceutical Preparations; Pharmacology; Phenotype; Potassium Channel; Research; Role; Shaw potassium channel protein family; Slice; Sodium Channel; Speed; Techniques; Testing; Time; Work; bean; dopaminergic neuron; experimental study; follow-up; hippocampal pyramidal neuron; inhibitor/antagonist; recruit; tool; voltage; voltage clamp

Contact PD/PI: BEAN, BRUCE P Project Summary/ Abstract The goal of the proposed research is to understand how the many types of ion channels present in a single neuron work together to produce the firing patterns of that neuron. Ultimately, we hope to use this knowledge to develop ion channel-targeted pharmacological agents that can differentially regulate firing of different types of neurons and thereby treat pathophysiological behavior such as epilepsy and ataxias. Previous grant periods focused on the functional roles of calcium channels, sodium channels, Kv2, and Kv4 potassium channels. The focus in the next grant period is to understand how different potassium channels combine to regulate the firing patterns of specific types of neurons and how inhibitors and enhancers of particular potassium channels differentially modify firing patterns of different neurons. We will follow up preliminary data showing that inhibition of BK and Kv3 potassium channels – including by the clinically-used drug 4-aminopyridine - often causes paradoxical slowing rather than speeding of firing. We will test two possible mechanisms for this effect: enhanced inactivation of Na channels or recruitment of other potassium channels with slower deactivation. A key element is to compare action potential firing in different types of neurons. We will focus on three examples of major electrophysiological phenotypes: hippocampal CA1 pyramidal neurons, cerebellar Purkinje neurons, and midbrain dopamine neurons. The experimental design will combine current clamp recordings of action potential firing with voltage- clamp analysis of the underlying currents, using both intact neurons in brain slice and acutely dissociated neurons, which allow fast voltage clamp to study gating on the rapid time scale of the action potential. A key feature of the approach will be to study both action potential firing and channel gating kinetics at 37 °C. Current clamp and voltage clamp experiments will be directly linked by the action potential clamp technique, in which recordings of natural firing behavior are used as voltage clamp commands to allow pharmacological dissection of the components of current generating patterns of action potentials. The research will include substantial characterization of pharmacological agents that block or enhance potassium channel subtypes, both as experimental tools and as possible leads for clinical drugs. Project Summary/Abstract Page 6

联系PD/PI：BEAN，布鲁斯P 项目总结/摘要 这项研究的目的是了解细胞中存在的多种离子通道是如何在细胞内形成的。 单个神经元一起工作以产生该神经元的放电模式。最终，我们希望利用这个 开发可差异调节放电的离子通道靶向药理学试剂的知识 不同类型的神经元，从而治疗病理生理行为，如癫痫和共济失调。 以前的资助期集中在钙通道，钠通道，Kv 2， Kv 4钾离子通道下一个资助期的重点是了解不同的钾 通道联合收割机来调节特定类型神经元的放电模式，以及抑制剂和 特定钾通道的增强剂差异性地改变不同神经元的放电模式。我们 将跟踪显示BK和Kv 3钾通道抑制的初步数据-包括 临床上使用的药物4-氨基吡啶-经常引起反常的减慢而不是加快放电。 我们将测试这种效应的两种可能机制：增强Na通道的失活或募集 其他钾离子通道失活较慢。一个关键因素是比较动作电位放电 不同类型的神经元。我们将重点介绍三个主要电生理表型的例子： 海马CA 1锥体神经元、小脑浦肯野神经元和中脑多巴胺神经元。 实验设计将结合动作电位放电的联合收割机电流钳记录和电压- 使用脑切片中的完整神经元和急性分离的神经元对潜在电流进行钳夹分析。 神经元，其允许快速电压钳以研究动作电位的快速时间尺度上的门控。一 该方法的关键特征将是在37 ℃下研究动作电位放电和通道门控动力学。 摄氏度。电流钳和电压钳实验将动作电位钳直接联系起来 技术，其中自然放电行为的记录被用作电压钳位命令，以允许 动作电位电流产生模式的成分的药理学剖析。的 研究将包括阻断或增强的药理学试剂的实质性表征， 钾通道亚型，既作为实验工具，也作为临床药物的可能线索。 项目摘要/摘要第6页