Physiological study on development of heart and its regulatory system during ontogeny in crustaceans

本研究的目的是阐明甲壳类动物心跳的个体发育和系统发育多样性及其调控机制。实验采用组织化学和电生理方法。结果表明：1)实现了等足类甲壳类动物异域Ligia群落的实验室饲养方法，并描述了异域Ligia的发育阶段。基于这些结果，我们发现在幼年发育过程中，异种Ligia的心脏起搏器从心肌转移到心脏神经节，心跳从肌源性转变为神经源性。此外，我们还发现成虫的神经源性心跳机制与其他甲壳类动物不同。2)我们在异种Ligia的中枢神经系统中发现了一对心脏抑制神经元和两对心脏加速神经元，表明这些心脏调节神经同时支配心脏神经节神经元和心肌。此外，我们发现在青少年发育过程中，与起搏器转移相关的心跳神经调节发生了发育变化。3)我们发现了异域Ligia幼年发育过程中激素调控的发育变化，特别是与起搏器转移相关的胺能调节心跳。(4)在原始甲壳类动物长尾三角龙（Triops longicaudatus）中发现了致肌性心脏，首次证明了甲壳类动物中存在致肌性心脏。我们就上述结果向专业期刊投稿了5篇论文，并已发表。我们正在准备另一些关于结果的论文。

The aim of the present study is to elucidate the ontogenetic and phylogenetic diversity of the heartbeat and its regulatory mechanisms in crustaceans. The experiments were performed using histochemical and electrophysiological methods. The results obtained were as follows : 1) We achieved the way to keep the colony of the isopod crustacean Ligia exotica in the laboratory and described its developmental stages. Based on these results, we showed that the heart pacemaker of Ligia exotica is transferred from the heart muscle to the cardiac ganglion during juvenile development and the heartbeat changes from myogenic to neurogenic. Moreover, we showed that the mechanism of the neurogenic heartbeat of the adults is different from that known previously in another crustaceans. 2) We identified one pair of cardioinhibitory and two pairs of cardioacceleratory neurons in the central nervous system of Ligia exotica, and showed that these cardioregulaory neurous innervate both the cardiac ganglion neurons and the myocardium. Moreover, we showed developmental changes in nervous regulation of the heartbeat associatd with the pacemaker transfer during juvenile development. 3) We showed developmental changes in hormonal regulation, especially in aminergic modulation of the heartbeat associated with the pacemaker transfer during juvenile development of Ligia exotica. 4) We found the myogeniic heartbeat in the primitive crustacean Triops longicaudatus and demonstrate first the presence of the myogenic heart in crustacea. We submitted five papers on the above results to professional journals and these papers have been published. We are preparing another some papers on the results.