Catecholamine-containing cells in larval and postlarval bivalve molluscs
Catecholamine-containing cells in larval and postlarval bivalve molluscs
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DOI：
10.2307/1542757
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发表时间：
1997-10-01
影响因子：
1.6
通讯作者：
Voronezhskaya, EE
中科院分区：
文献类型：
--
作者：
Croll, RP;Jackson, DL;Voronezhskaya, EE
以往的研究表明，参与控制的几个幼虫的行为，如摄食，运动，诱导沉降和变态的儿茶酚胺。在本研究中，我们采用了甜菜碱诱导的，蓝绿色荧光，以指示细胞内的代表两个双壳类，果胶（Placopecten magellanicus）和贻贝（贻贝）。在定居前和定居后不久，对不同发展阶段的幼虫进行了检查。荧光细胞的分布在两个物种中是相似的。面盘中期，在每个软腭叶的外缘沿着分布着几个荧光细胞和荧光纤维，在口的侧面分布着一对瓶状细胞。一个单一的纤维从附近的嘴突出到一个地区下面的顶端簇。在pediveliger中，口部的细胞由另外两到四个荧光细胞连接。发育中的足也含有许多这样的细胞，其中一些细胞具有穿透“鞋底”上的上皮的突起，并具有纤毛末梢。荧光胞体也位于地幔的边缘。中央突出的纤维似乎终止于足和腹部神经节，其中还包含一些荧光胞体。定居后，软膜叶和常驻荧光胞体消失，但荧光细胞在脚坚持这后一个器官的增长。鳃内的荧光细胞通过纤维与腹神经节相连。用血清素抗体标记的对照制剂表明，吲哚胺诱导的荧光不是由于吲哚胺的存在。本研究不仅证实了以前的色谱证据表明，在双壳类软体动物的幼虫中存在的儿茶酚胺，但也确定了假定的神经元电路，可能控制各种幼虫的行为。
Previous studies have suggested an involvement of catecholamines in the control of several larval behaviors, such as feeding, locomotion, and induction of settling and metamorphosis. In the present study we employed aldehyde-induced, blue-green fluorescence to indicate catecholamines in cells within representatives of two bivalve families, the Pectinidae (Placopecten magellanicus) and the Mytilidae (Mytilus edulis). Larvae were examined at different stages of development before and also shortly after settlement. The general distribution of fluorescent cells was similar in the two species. By mid-veliger stage, several fluorescent cells and fibers were located along the outer rim of each velar lobe, and a pair of flask-shaped cells was located lateral To the mouth. A single fiber from near the mouth projected to a region beneath the apical tuft. In the pediveliger, the cells by the mouth were joined by an additional two to four fluorescent cells. The developing foot also contained numerous such cells, some of which had processes that penetrated the epithelium on the ''sole'' and bore ciliated terminals. Fluorescent somata were also located around the edge of the mantle. Centrally projecting fibers appeared to terminate in the pedal and abdominal ganglia, which also contained a few fluorescent somata. After settlement, the velar lobes and resident fluorescent somata disappeared, but fluorescent cells in the foot persisted as this latter organ grew. Fluorescent cells within the developing gill were connected with the abdominal ganglia by means of fibers. Control preparations labeled with antibodies raised against serotonin indicated that the aldehyde-induced fluorescence was not due to the presence of indoleamines. The present study not only confirms previous chromatographic evidence suggesting the presence of catecholamines in the larvae of bivalve molluscs, but also identifies putative neuronal circuits that may control various larval behaviors.