Summary
Ultrastructural evidence is given of the occurrence of nervous elements in the mesoglea of Ctenophores based on the presence of the typical synapses of this phylum.
In Beroids, nervous fibers from the ectodermal nerve-net cross the epithelial basal membrane and run through the mesoglea; they are devoid of any ensheathing cell. These neurites build highly differentiated synapses upon the muscles and upon peculiar cells, tentatively named mesenchymal cells.
In Cydippids, nerve fibers and nerve cell-bodies have been observed in the mesoglea of the tentacles. The mesogleal core of each tentacle contains mesenchymal cells and a thick strand of neurons and neurites, forming a kind of elongated ganglion. Neurites of either the axial neurones or the epithelial nerve-net neurones form numerous radial nerve strands across the tentacular muscles. Interneural, neuro-muscular and neuro-mesenchymal junctions are very frequent in the tentacle.
As far as the organization of the mesoglea is concerned, the Ctenophora thus appear closer to Turbellaria than to Cnidaria.
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Bibliographie
Bargmann, W., Jacob, K., Rast, A.: Über Tentakel und Colloblasten der Ctenophore Pleurobrachia pileus. Z. Zellforsch. 123, 121–152 (1972)
Batham, E.J., Pantin, C.F.A., Robson, E.A.: The nerve net of the sea anemone Metridium senile: the mesenteries and the column. Quart. J. micr. Sci. 101, 487–510 (1960)
Batham, E.J., Pantin, C.F.A., Robson, E.A.: The nerve net of the sea anemone Metridium senile: artifacts and the nerve net. Quart. J. micr. Sci. 102, 143–156 (1961)
Bethe, A.: Der subepitheliale Nervenplexus der Ctenophoren. Biol. Zbl. 15, 140–145 (1895)
Buisson, B.: Les supports morphologiques de l'intégration dans la colonie de Veretillum cynomorium Pall. (Cnidaria, Pennatularia). Z. Morph. Tiere 68, 1–36 (1970)
Buisson, B., Franc, S.: Structure et ultrastructure des cellules mésenchymateuses et nerveuses intramésogléennes de Veretillum cynomorium Pall. Vie et Milieu 20, 2A, 279–292 (1969)
Heider, K.: Vom Nervensystem der Ctenophoren. Z. Morph. Ökol. Tiere 9, 638–678 (1927)
Hernandez-Nicaise, M.-L.: Specialized connexions between nerve cells and mesenchymal cells in Ctenophores. Nature (Lond.) 217, 1075–1076 (1968)
Hernandez-Nicaise, M.-L.: Le système nerveux des Cténaires. I. Structure et ultrastructure des réseaux épithéliaux. Z. Zellforsch. 137, 223–250 (1973)
Hernandez-Nicaise, M.-L.: The nervous system of Ctenophora. III. Ultrastructure of synapses. J. Neurocytol. 2 (sous presse)
Hertwig, R.: Über den Bau der Ctenophoren. Jen. Z. Naturw. 14, 393–457 (1880)
Horridge, G.A.: Relations between nerves and cilia in Ctenophores. Amer. Zool. 5, 357–375 (1965a)
Horridge, G.A.: Non-motile sensory cilia and neuromuscular junctions in a ctenophore independent effector organ. Proc. roy. Soc. B 162, 333–350 (1965b)
Horridge, G.A.: Interneurons. London: Freeman & Co 1968
Horridge, G.A., Mackay, B.: Neurociliary synapses in Pleurobrachia (Ctenophora). Quart. J. micr. Sci. 105, 163–174 (1964)
Korn, H.: Zum Nervensystem der Ctenophore Pleurobrachia pileus O. Müller. Zool. Anz. 163, 351–359 (1959)
Mackie, G.O.: The structure of the nervous system in Velella. Quart. J. micr. Sci. 101, 119–131 (1960)
Mackie, G.O., Passano, L.M.: Epithelial conduction in Hydromedusae. J. gen. Physiol. 52, 600–621 (1968)
Nicaise, G.: The gliointerstitial system of Molluscs. Int. Rev. Cytol. 34, 251–332 (1973)
Pantin, C.F.A.: The elementary nervous system. Proc. roy. Soc. B 140, 147–168 (1952)
Pantin, C.F.A.: Diploblastic animals. Proc. linn. Soc. Lond. 171, 1–14 (1960)
Pavans de Ceccatty, M., Buisson, B.: Le système nerveux intramésogléen dans les colonies de Veretillum cynomorium Pall. (Cnidaire Pennatulidae). C. R. Acad. Sci. (Paris) 259, 3611–3613 (1964)
Pavans de Ceccatty, M., Hernandez, M.L., Thiney, Y.: Système nerveux et musculature chez Beroe forskali Chun 1880. C. R. Acad. Sci. (Paris) 254, 3241–3243 (1962)
Tregouboff, G., Rose, M.: Manuel de Planctonologie Méditerranéenne. Paris: C.N.R.S. Ed. 1957
Ungewitter, L.H.: An urea silver method for nerve fibers and nerve endings. Stain Technol. 26, 73–76 (1951)
Westfall, J.A.: Synapses in a sea-anemone, Metridium (Anthozoa). 7ème Congr. int. Micr. electron. Grenoble, Paris: Sté franc. Micr. electron. Ed. 1970a
Westfall, J.A.: Ultrastructure of synapses in a primitive coelenterate. J. Ultrastruct. Res. 32, 237–246 (1970b)
Westfall, J.A.: The nematocyte complex in a Hydromedusan, Gonionemus vertans. Z. Zellforsch. 110, 457–470 (1970c)
Westfall, J.A.: Ultrastructural evidence for a granule-containing sensory-motor-interneuron in Hydra littoralis. J. Ultrastruct. Res. 42, 268–282 (1973)
Westfall, J.A., Yakamata, S., Enos, D. E.: An ultrastructural survey of synapses in tentacles of coelenterates. Amer. Zool. 10, 512 (1970a)
Westfall, J. A., Yakamata, S., Enos, P. D.: Ultrastructure of synapses in Hydra. J. Cell Biol. 47, 226a (1970b)
Westfall, J.A., Yakamata, S., Enos, P.D.: Ultrastructural evidence of polarized synapses in the nerve net of Hydra. J. Cell Biol. 51, 318–323 (1971)
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Ce travail correspond à la deuxième partie d'une thèse de Doctorat d'Etat intitulée: «Système nerveux et intégration chez les Cténaires». Il a été effectué au sein de l'Equipe de Recherches Associée au C.N.R.S. no 183 (Directeur: Dr. Max Pavans de Ceccatty) et avec le concours du Centre de Microscopie Electronique Appliquée à la Biologie, de l'Université Claude Bernard.
Ce travail a bénéficié de la collaboration technique de Madame J. Amsellem que nous remercions vivement.
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Hernandez-Nicaise, ML. Le système nerveux des cténaires. Z.Zellforsch 143, 117–133 (1973). https://doi.org/10.1007/BF00307455
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DOI: https://doi.org/10.1007/BF00307455