Regulation of the crab heartbeat by FMRFamide-like peptides: Multiple interacting effects on center and periphery
Regulation of the crab heartbeat by FMRFamide-like peptides: Multiple interacting effects on center and periphery
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DOI：
10.1152/jn.00558.2007
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发表时间：
2007-11-01
影响因子：
2.5
通讯作者：
Miller, Mark W.
中科院分区：
文献类型：
--
作者：
Fort, Timothy J.;Brezina, Vladimir;Miller, Mark W.
我们正在研究一个简单的中央模式发生器（CPG）效应器系统，蓝蟹的心脏的神经调节行动的功能“逻辑”。心脏的节律性收缩是神经性的，由心脏神经节（CG）产生的节律性运动模式驱动。本文采用解剖学和生理学方法研究了FMRFamide样肽（FLP）TNRNFLRFamide（F-1）、SDRNFLRFamide（F-2）和GYNRSFLRFamide（一种真正的Callinectes FLP）的来源及其对系统的作用。免疫组织化学定位显示，在心包器官（PO），从调制器释放到心脏作为循环神经激素的FLP免疫反应纤维丛。结合回填和免疫组化实验表明，在PO的FLP起源于中枢神经系统，从大的神经分泌细胞在B集群的第一胸神经节。在生理学实验中，我们检查了FLP对完整工作心脏的作用，在半完整的心脏中，我们可以记录运动模式以及肌肉收缩，在孤立的CG上，以及在开发用于评估对肌肉的直接作用的制剂中，运动神经元尖峰的受控模式。FLP具有较强的正性变时和变力作用。对这些效应的分析表明，它们是通过FLP对心肌和CG施加的至少两种主要作用产生的。这些主要行为引发了许多由前馈和反馈相互作用介导的次要后果，这些相互作用整合了完整的、偶联的CPG效应器系统的活动。
We are studying the functional "logic" of neuromodulatory actions in a simple central pattern generator (CPG)-effector system, the heart of the blue crab Callinectes sapidus. The rhythmic contractions of this heart are neurogenic, driven by rhythmic motor patterns generated by the cardiac ganglion (CG). Here we used anatomical and physiological methods to examine the sources and actions on the system of the FMRFamide-like peptides (FLPs) TNRNFLRFamide (F-1), SDRNFLRFamide (F-2), and GYNRSFLRFamide, an authentic Callinectes FLP. Immunohistochemical localization revealed a plexus of FLP-immunoreactive fibers in the pericardial organs (POs), from which modulators are released to reach the heart as circulating neurohormones. Combined backfill and immunohistochemical experiments indicated that the FLPs in the POs originated in the CNS, from large neurosecretory cells in the B cluster of the first thoracic neuromere. In physiological experiments, we examined the actions of the FLPs on the intact working heart, on the semi-intact heart in which we could record the motor patterns as well as the muscle contractions, on the isolated CG, and in a preparation developed to assess direct actions on the muscle with controlled patterns of motor neuron spikes. The FLPs had strong positive chronotropic and inotropic effects. Dissection of these effects suggested that they were produced through at least two primary actions of the FLPs exerted both on the heart muscle and on the CG. These primary actions elicited numerous secondary consequences mediated by the feedforward and feedback interactions that integrate the activity of the complete, coupled CPG-effector system.