Neural coupling mechanisms of cardiac output and haemolymph distribution in myogenic hearts

日本柳螺属于最原始的软体动物类群——腹足纲。就像几乎所有关于循环系统的研究一样，腹足纲、双壳纲和头足纲的物种都被利用了，据我们所知，这项利用石壳的研究是对石壳心血管系统的第一次重大研究。(1)心肌性心跳。心脏接受来自外侧和内脏神经索的兴奋性和抑制性神经。(2)心包表现出节律性心脏，同时接收来自外侧和内脏神经索的兴奋性和抑制性神经。缓慢的去极化电位先于心包的尖峰电位和平台电位。这表明心包搏动是肌源性的。(3)甲舍肽对兴奋神经刺激对心脏的拮抗作用。在心脏和心包膜中观察到血清素样免疫反应性神经过程。这些结果表明兴奋性心脏神经…更多的可能是血清素能。(4)机械羟胆碱可阻断抑制性心神经对心脏的刺激作用。抑制性神经可能是胆碱能神经。诸如CARP（捕获放松肽）和FMRF酰胺等肽抑制心脏和心包活动。在心包和心脏均观察到carp和FMRF酰胺样免疫反应性神经过程。我们不能排除抑制性心神经涉及含有肽的轴突或同时含有肽和乙酰胆碱的轴突的可能性。在腹足动物黑腹海蛾和加利福尼亚海蛾中，腹部神经节神经元L7与鳃神经节神经元进行突触接触。L7对鳃肌的兴奋作用被腹部神经节中一个新发现的神经元所抑制。在腹足动物胸膜鳃胚中，血清素样免疫反应细胞首先出现在栉水母中。在大鼠脑连接区出现了血清素能细胞的幼虫群。从幼年到幼体的蜕变过程中，星系团消失。家蚕（Bombyx mori）的心脏显示肌源性跳动。在额神经节中发现了一个负责触发反节律性心跳的神经元。少

Liolophura japonica is belonging to the most primitive molluscan taxa, Archiogastropoda. As in almost all studies on the circulatory system, species in Gastropoda, Bivalvia and Cephalopoda have been employed, this study using the chiton Liolophula is, to our knowledge, the first major study on the cardiovascular system of the chiton.1. (1) Heart beats occurred myogenically. The heart received both exciatory and inhibitory nerves from both the lateral and visceral nerve cords.(2) The pericardium showed rhythmic hearts, and received both excitatory and inhibitory nerves from both the lateral and visceral nerve cords. Slow depolarizing potentials preceded spike and plateau potetials of the pericardium. This indicates that pericardial beats occured myogenically.(3) Methysergide antagonized effects of stimulation of excitatory nerves on the heart. Serotonin-like immunoreactive neural processes were observed in the heart and pericardium. These results indicate that excitatory cardiac nerves … More may be serotonergic.(4) Effects of stimulation of inhibitory cardiac nerves on the heart were blocked by mechylxylocholine. Inhibirory nerves may be cholinergic. Peptides such as CARP (catch relaxing peptide) and FMRF amide depressed cardiac and pericardial actions. CARP-and FMRF amide-like immunoreactive neural processes were observed in both the pericardium and the heart. We cannot exclude the possibility that the inhibitory cardiac nerve involves axons containing the peptides or axons containing both co-existing peptide and ACh.2.In the gastropod Aplysia kurodai and A.californica an abdominal ganglionic neuron L7 makes synaptic contact with branchial ganglionic neurons. Excitatory effects of L7 on the gill muscle were depressed by a newly identified neuron in the abdominal ganglion.3.In the embryo of the gastropod Pleurobranchaea, serotonin-like immunoreactive cells first appeared in the trochophore. A larval serotonergic cell cluster appeared in the cerebral commissure in the veliger. The cluster disappeared at metamorphosis from veliger to the juveneile.4.In the silkworm Bombyx mori, the heart shows myogenic beats. A neuron responsible for triggering antidromically conducted heart beat was identified in the frontal ganglion. Less