A new sensory organ in "primitive" molluscs (Polyplacophora: Lepidopleurida), and its context in the nervous system of chitons.
A new sensory organ in "primitive" molluscs (Polyplacophora: Lepidopleurida), and its context in the nervous system of chitons.
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DOI：
10.1186/1742-9994-11-7
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发表时间：
2014-01-21
影响因子：
2.8
通讯作者：
Schrödl M
中科院分区：
文献类型：
--
作者：
Sigwart JD;Sumner-Rooney LH;Schwabe E;Heß M;Brennan GP;Schrödl M
石鳖（多板目）是软体动物，被认为有一个简单的神经系统，没有头部化。在软体动物类的位置是广泛辩论的主题和神经解剖特征可以提供系统发育数据的新来源，以及对生物体的基本生物学的见解。我们报告了一个新的离散的前感觉结构石鳖，发生在整个Lepidopleurida，为了生活石鳖，保留plesiomorphic特征。在活体动物上，这种新颖的“施瓦贝器官”是一对棕色或紫色的色素条纹，位于套囊腔的顶部，位于口舌的侧面或部分被口舌覆盖。我们描述了组织学和超微结构的前神经系统，包括施瓦贝器官，在两个lepidopleuran石鳖，使用光镜和电镜。食管神经环明显增大，呈神经节样结构，神经节被神经胞体包围。施瓦贝器官由外侧神经索支配，穿过施瓦贝器官上皮的密集神经纤维束经常被包裹该器官的色素颗粒包围。基底细胞突出到上皮表面和细胞轴承大量的纤毛结构可能是指示的感觉功能。施瓦贝器官存在于所有属内Lepidopleurida（和缺席整个Chitonida），并代表了一个新的解剖学突触的分支。施瓦贝器官是一种色素感觉器官，发现于深海和浅水石鳖的腹面;虽然其解剖结构已被充分了解，但其功能仍然未知。石鳖食管神经环的前连合可以被认为是大脑。我们的全面审查石鳖中枢神经系统，特别是感觉器官的苍白球腔，提供了一个背景下，解释神经解剖同源性和评估这个新的感觉器官。
Chitons (Polyplacophora) are molluscs considered to have a simple nervous system without cephalisation. The position of the class within Mollusca is the topic of extensive debate and neuroanatomical characters can provide new sources of phylogenetic data as well as insights into the fundamental biology of the organisms. We report a new discrete anterior sensory structure in chitons, occurring throughout Lepidopleurida, the order of living chitons that retains plesiomorphic characteristics. The novel “Schwabe organ” is clearly visible on living animals as a pair of streaks of brown or purplish pigment on the roof of the pallial cavity, lateral to or partly covered by the mouth lappets. We describe the histology and ultrastructure of the anterior nervous system, including the Schwabe organ, in two lepidopleuran chitons using light and electron microscopy. The oesophageal nerve ring is greatly enlarged and displays ganglionic structure, with the neuropil surrounded by neural somata. The Schwabe organ is innervated by the lateral nerve cord, and dense bundles of nerve fibres running through the Schwabe organ epithelium are frequently surrounded by the pigment granules which characterise the organ. Basal cells projecting to the epithelial surface and cells bearing a large number of ciliary structures may be indicative of sensory function. The Schwabe organ is present in all genera within Lepidopleurida (and absent throughout Chitonida) and represents a novel anatomical synapomorphy of the clade. The Schwabe organ is a pigmented sensory organ, found on the ventral surface of deep-sea and shallow water chitons; although its anatomy is well understood, its function remains unknown. The anterior commissure of the chiton oesophagial nerve ring can be considered a brain. Our thorough review of the chiton central nervous system, and particularly the sensory organs of the pallial cavity, provides a context to interpret neuroanatomical homology and assess this new sense organ.
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DOI：
10.1016/0305-0491(72)90094-6
发表时间：
1972-01-01
期刊：
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY
影响因子：
--
作者：
BENJAMIN, PR;WALKER, TS
通讯作者：
WALKER, TS
DOI：
10.1098/rstb.1987.0002
发表时间：
1987-02-12
影响因子：
6.3
作者：
HASZPRUNAR, G
通讯作者：
HASZPRUNAR, G
影响因子：
2.5
作者：
FRAZIER, WT;KANDEL, ER;COGGESHALL, RE
通讯作者：
COGGESHALL, RE
影响因子：
--
作者：
Arey, LB;Crozier, WJ
通讯作者：
Crozier, WJ
DOI：
10.1007/bf00335443
发表时间：
1969-01-01
期刊：
ZEITSCHRIFT FUR ZELLFORSCHUNG UND MIKROSKOPISCHE ANATOMIE
影响因子：
--
作者：
BOYLE, PR
通讯作者：
BOYLE, PR