ION CHANNELS IN MECHANOSENSITIVE NEURONS

机械敏感神经元中的离子通道

基本信息

批准号：
6125977
负责人：
DIANA L KUNZE
金额：
$ 21.5万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-12-01 至 2003-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6125977
关键词：
action potentials antisense nucleic acid baroreceptors baroreflex confocal scanning microscopy electrophysiology immunocytochemistry in situ hybridization mathematical model membrane potentials membrane structure neuroregulation polymerase chain reaction potassium channel vascular smooth muscle nervous control voltage gated channel

项目摘要

We are studying the expression of voltage-gated ion channels in the soma and terminals of baroreceptor neurons whose mechanosensitive terminals lie in the adventitia of walls of major arteries. We have proposed that these channels underlie the markedly different firing patterns of the receptors connected to unmyelinated versus myelinated fibers as they respond to changes in arterial pressure. In particular, this proposal focuses on the identification, followed by functional assessment, of the specific voltage-gated potassium channels. These channels shape the action potential and discharge patterns and they are frequent targets of neuromodulators. In the first aim we will determine which of the members of the potassium channel families, Kvl, Kv2, Kv3 and Kv4, are present in the soma of baroreceptor neurons through the use of RT-PCR, in situ hybridization and channel specific antibodies. In aim two we will move to the peripheral terminal, the actual baroreceptor, to ask whether the channels that are present in the soma are also present on the peripheral terminals. We will use immunocytochemical techniques to explore the distribution of the ion channels within the terminals of both myelinated and unmyelinated fibers using confocal microscopy. In Aim 3 we will examine the functional role of the specific potassium channels. To do this we are using anti-sense strategy in identified baroreceptor neurons. The contributions of a distinct channel to resting membrane potential, action potential and to the discharge produced by depolarization will be examined. Finally, in Aim 4 we will tie together the electrophysiological characterization with anatomical localization of the channels identified in AIMS 1-3 in mathematical models that allow us to make testable predictions for the role of each of these channels A and C baroreceptor neurons.

我们正在研究压力感受器神经元体和末端中电压门控离子通道的表达，压力感受器神经元的机械敏感末端位于主动脉壁的外膜中。我们提出，这些通道是与无髓纤维和有髓纤维相连的受体在响应动脉压变化时明显不同的放电模式的基础。特别是，该提案侧重于特定电压门控钾通道的识别，然后进行功能评估。这些通道塑造动作电位和放电模式，它们是神经调节剂的常见目标。在第一个目标中，我们将通过使用 RT-PCR、原位杂交和通道特异性抗体来确定钾通道家族的哪些成员 Kv1、Kv2、Kv3 和 Kv4 存在于压力感受器神经元的体细胞中。在目标二中，我们将转向外周终端，即实际的压力感受器，以询问体细胞中存在的通道是否也存在于外周终端上。我们将使用免疫细胞化学技术，通过共聚焦显微镜探索有髓纤维和无髓纤维末端内离子通道的分布。在目标 3 中，我们将研究特定钾通道的功能作用。为此，我们在已识别的压力感受器神经元中使用反义策略。将检查不同通道对静息膜电位、动作电位和去极化产生的放电的贡献。最后，在目标 4 中，我们将在数学模型中将电生理学特征与 AIMS 1-3 中确定的通道的解剖定位结合起来，使我们能够对通道 A 和 C 压力感受器神经元的作用做出可测试的预测。