Basiepidermal nervous system in Nemertoderma westbladi (Nemertodermatida):: GYIRFamide immunoreactivity
Basiepidermal nervous system in Nemertoderma westbladi (Nemertodermatida):: GYIRFamide immunoreactivity
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DOI：
10.1016/j.zool.2003.12.002
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发表时间：
2004-01-01
期刊：
影响因子：
2
通讯作者：
Jondelius, U
中科院分区：
文献类型：
--
作者：
Raikova, OI;Reuter, M;Jondelius, U
Nemertodermatida是一种微小的海洋蠕虫。最近的分子研究表明，它们很可能是现存最早的双边动物。双边动物祖先的神经系统是什么样的？为了回答这一问题，采用间接免疫荧光技术和共聚焦扫描激光显微镜对西叶奈梅特霉的神经网络进行了研究。扁虫神经肽GYIRFamide抗体与抗血清素抗体和phalloidin-TRITC染色联合使用。免疫染色显示全基表皮NS。位于体壁肌肉组织外的静泡水平上的一个环形成了唯一的集中，即“大脑”。未观察到口胃NS。“大脑”的GYIRFamide免疫反应部分由松散堆积的神经纤维组成，其中有多个小神经元和几个大神经元。神经系统的肽能和胺能模式并不相互对应：前者在腹侧更发达，后者在背侧更明显。一对GYIRFamide免疫反应神经索支配着动物的腹侧、嘴巴和雄性生殖器开口。迄今为止所研究的奈米托皮虫未显示出共同的NS模式。讨论了无胚动物可能的突触形态。研究表明，除Xenoturbellida外，nemertodermatid NS具有许多多形特征，比其他蠕虫的NS更原始。据推测，双侧祖先只有一个基底表皮神经网络，没有集中的脑样结构，也没有口胃神经系统。(C) 2004 Elsevier GmbH版权所有。
The Nemertodermatida are a small group of microscopic marine worms. Recent molecular studies have demonstrated that they are likely to be the earliest extant bilaterian animals. What was the nervous system (NS) of a bilaterian ancestor like? In order to answer that question, the NS of Nemertoderma westbladi was investigated by means of indirect immunofluorescence technique and confocal scanning laser microscopy. The antibodies to a flatworm neuropeptide GYIRFamide were used in combination with anti-serotonin antibodies and phalloidin-TRITC staining. The immunostaining revealed an entirely basiepidermal NS. A ring lying outside the body wall musculature at the level of the statocyst forms the only centralisation, the "brain". No stomatogastric NS has been observed. The GYIRFamide immunoreactive part of the "brain" is formed of loosely packed nerve fibres with multiple small neurones and a few large ones. The peptidergic and aminergic patterns of the NS do not correspond to each other: the former is more developed on the ventral side, the latter is more pronounced on the dorsal side. A pair of GYIRFamide immunoreactive nerve cords innervates the ventral side of the animal, the mouth and the male genital opening. The nemertodermatids studied to-date display no common NS pattern. Possible synapomorphies of the Acoelomorpha are discussed. The study demonstrates that the nemertodermatid NS possesses a number of plesiomorphic features and appears more primitive than the NS in other worms, except the Xenoturbellida. The bilaterian ancestor supposedly possessed only a basiepidermal nerve net and had no centralised brain-like structures and no stomatogastric NS. (C) 2004 Elsevier GmbH. All rights reserved.