TRANSMITTER INTERACTION IN A CARDIAC GANGLION

心神经节中发射机的相互作用

• 批准号: 3408170
• 负责人: Rodney L Parsons
• 金额: $ 15.1万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-09-01 至 1996-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3408170
• 关键词: Urodela; acetylcholine; autonomic ganglion; calcitonin gene related peptide; cell membrane; dopamine; electron microscopy; electrophysiology; fluorescent dye /probe; fresh water environment; heart conduction system; heart innervation; histochemistry /cytochemistry; immunochemistry; membrane potentials; neural transmission; neurochemistry; neurons; neuropeptides; neurotransmitter metabolism; neurotransmitters; parasympathetic nervous system; postganglionic fiber; preganglionic fiber; serotonin; substance P; synapses; tissue /cell culture; voltage /patch clamp

The cardiac ganglion of the mudpuppy, Necturus maculosus, is an excellent model system for analysis of synaptic integration within a vertebrate cardiac ganglion. Two neuron types are present: parasympathetic postganglionic neurons and SIF cells. The SIF cells contain a number of neurotransmitters including: catecholamines, 5-HT, a substance P-like peptide and a galanin-like peptide. Further, there is an extensive substance P/GGRP immunoreactive afferent fiber input into the cardiac ganglion which make pericellular complexes around postganglionic neurons and SIF cells. We will establish the mechanism(s) by which the afferent fiber and SIF cell input influence the activity of the postganglionic neurons. The following specific questions will be addressed: a) Determine the function and source of the afferent transmission and on the conductance properties of the postganglionic neurons. Immunocytochemical and tracing studies will be done to establish the central origin (i.e., vagal versus spinal) and the peripheral distribution of the substance P/GGRP-immunoreactive fibers. b) Establish the role of SIf cells in the cardiac ganglion. Sif cells will be stimulated while recording from adjacent postganglionic neurons to test whether SIF cells influence postganglionic neuron activity. We will test whether the SIF cells respond to ACh, substance P and CGRP to establish whether these cells are activated by preganglionic and/or afferent transmitters. The action of other neurotransmitters, present in SIF cells such as 5-HT and dopamine, on the membrane properties of postganglionic neurons and ganglionic transmission will be tested. c) Establish the mechanism(s) by which galanin alters, excitability of the postganglionic neurons. The influence of galanin on membrane currents in isolated postganglionic neurons will be determined using cell attached patch and whole cell voltage clamp techniques. The kinetic properties of the galanin activated potassium conductance will be determined using cell attached patch and whole cell voltage clamp techniques. The kinetic properties of the galanin activated potassium conductance, will be determined from single channel activity. An analysis of galanin induced alteration of calcium and potassium conductances will be performed using whole cell voltage clamp procedures. This project will provide important new information in three areas: a) the mechanism(s) of action of specific neurotransmitters on an identified postsynaptic cell, b) the role(s) of SIF cells in autonomic ganglia, and c) the role of afferent fiber input and type (s) of integration which may occur in vertebrate cardiac ganglia that are important in local reflex control of cardiac function.

泥中的心脏神经节，麦卢斯花，是一个极好的 用于分析脊椎动物内突触整合的模型系统 心脏神经节。存在两种神经元类型：副交感神经 后神经神经元和SIF细胞。 SIF单元包含许多 神经递质包括：儿茶酚胺，5-HT，一种类似物质的物质 肽和甘酸酯样肽。此外，还有一个广泛的 物质P/GGRP免疫反应性传入纤维输入心脏 神经节使周围神经元周围的细胞周围复合物 和SIF细胞。我们将建立传入的机制 纤维和SIF细胞输入会影响囊后的活性 神经元。将解决以下特定问题：a）确定 传入传输的功能和来源 后神经节神经元的电导特性。免疫细胞化学 并将进行追踪研究以建立中心起源（即 迷走神经与脊柱）和物质的外围分布 p/ggrp-免疫反应纤维。 b）确定SIF细胞在 心脏神经节。从记录中，将刺激SIF单元 邻近的后神经节神经元测试SIF细胞是否影响 后神经神经元活性。我们将测试SIF单元是否 响应ACH，物质P和CGRP以确定这些细胞是否为 被甘氏原子和/或传入发射器激活。动作 其他神经递质，存在于5-HT和多巴胺等SIF细胞中， 在后神经神经元和神经节的膜特性上 传输将进行测试。 c）建立机制 Galanin改变了刺激后神经元的兴奋性。影响 在隔离后神经神经元中的膜电流上的galanin将 使用连接的细胞和全细胞电压夹确定 技术。加拉宁活化钾的动力学特性 电导将使用连接的细胞和全细胞确定 电压夹技术。 Galanin激活的动力学特性 钾电导将根据单通道活性确定。 Galanin诱导的钙和钾改变的分析 电导将使用全细胞电压夹程序进行。 该项目将在三个领域提供重要的新信息：a） 特定神经递质在已识别的特定神经递质的作用机制 突触后细胞，b）自主神经节中SIF细胞的作用， c）可能的传入纤维输入和集成类型的作用 发生在局部反射中很重要的脊椎动物心脏神经节中 控制心脏功能。