Pernet Vincent, Anctil Michel, Grimmelikhuijzen Cornelis J P
Département de Sciences Biologiques and Centre de Recherche en Sciences Neurologiques, Université de Montréal, Montréal, Québec H3C 3J7, Canada.
J Comp Neurol. 2004 Apr 26;472(2):208-20. doi: 10.1002/cne.20108.
The neuropeptide Antho-RFamide is extremely abundant in Renilla koellikeri (sea pansy), a representative of the cnidarians (octocorallians) considered to be closest to the stem ancestors of metazoans with nervous systems. Therefore, a knowledge of the distribution of Antho-RFamide-containing neurons in this species would contribute to our understanding of the early evolution of nervous systems. Using antisera raised against RFamide and FMRFamide, we detected immunostaining in numerous neurons throughout the nervous system of the sea pansy. The antisera revealed ectodermal nerve-nets on the upper and lower sides of the colony and on the oral side of tentacles, in the oral disk, and in the pharynx of feeding polyps. Neurons were immunostained also in the mesogleal nerve-net of feeding polyps and in the through-conducting mesogleal nerve-net of the colonial mass. Varying densities of stained neurons were observed in the different compartments of the endoderm: muscular walls of the feeding and water circulation polyps, mesenteric filaments and their derived follicles containing either ovocytes or spermatophores, in the endodermal channels connecting the different compartments of the colony, and in circular muscle of the peduncle. The distribution of immunostained neurons suggests that they play important roles in feeding, reproduction, neuromuscular transmission, and in neuro-neuronal transmission coordinating the different parts of the colony.
神经肽Antho-RFamide在红珊瑚（海笔）中极为丰富，红珊瑚是刺胞动物（八放珊瑚亚纲）的代表，被认为是最接近具有神经系统的后生动物祖先的物种。因此，了解该物种中含Antho-RFamide神经元的分布情况将有助于我们理解神经系统的早期进化。我们使用针对RFamide和FMRFamide产生的抗血清，在海笔的整个神经系统中的众多神经元中检测到了免疫染色。抗血清显示在群体的上侧和下侧、触手的口侧、口盘以及摄食息肉的咽中存在外胚层神经网。在摄食息肉的中胶层神经网以及群体块的贯穿传导中胶层神经网中，神经元也呈免疫染色。在内胚层的不同区域观察到了不同密度的染色神经元：摄食和水循环息肉的肌肉壁、肠系膜丝及其包含卵母细胞或精子托的衍生滤泡、连接群体不同区域的内胚层通道以及柄的环形肌肉。免疫染色神经元的分布表明它们在摄食、繁殖、神经肌肉传递以及协调群体不同部分的神经-神经传递中发挥着重要作用。
