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Dopaminergic systems in the European eel: characterization, brain distribution, and potential role in migration and reproduction

  • FISH AND DIADROMY IN EUROPE
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Abstract

In fish like in mammals, dopamine (DA) is a major catecholaminergic neurotransmitter that contributes to many functions of the nervous system like sensory perception, tuning of sensori-motor cues, and hypothalamic and pituitary functions. In the eel, DA inhibits gonadal development, and juvenile silver eels remain blocked at a prepubertal stage if their reproductive migration does not occur. From data in other teleosts and vertebrates, it is suggested that DA would be involved also in the last steps of eel reproduction (oocyte maturation, ovulation, and spermiation) as well as in eel reproductive migration (locomotion and olfaction). Investigating dopaminergic systems in the eel may help in understanding the mechanisms of its complex life cycle and provide new data for its conservation and reproduction. In this article we review the biosynthesis and catabolism of catecholamines and discuss available methods to investigate brain dopaminergic systems in vertebrates and their application to the eel. Immunocytochemistry, in situ hybridization, and different tracing methods are used to map dopaminergic neurons and projections in the brain and pituitary and infer their potential functions. Moreover, variations in dopaminergic activity may be approached by means of quantitative methods like quantitative real-time RT-PCR and HPLC. These tools are currently used to study dopaminergic systems in the eel brain, their anatomy, regulation, and potential roles with special emphasis on the regulation of reproduction and reproductive migration.

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Acknowledgments

We are grateful to Dr. P. Sébert and Dr. P. Vernier for their hospitality and for their advice, and to Dr. M. Wulliman and Dr. M. Kapsimali for helpful discussions on brain neuroanatomy. This work was partly supported by the European project EELREP (Project No. Q5RS-2001-01836). M.-E. Sébert is a recipient of an MNRT Ph.D. fellowship and Dr. F.-A. Weltzien of a postdoctoral European Marie Curie Individual Fellowship (No. MCFI-2002-01609).

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  1. Département des Milieux et Peuplements Aquatiques, Muséum National d’Histoire Naturelle, USM 0401, UMR 5178 CNRS/MNHN/UPMC Biologie des Organismes Marins et Ecosystèmes, 75231, Paris Cedex 05, France

    Marie-Emilie Sébert, Finn-Arne Weltzien & Sylvie Dufour

  2. Unité Haute Pression et Métabolisme, UPCI-EA3879, Faculté des Sciences, 6 avenue Le Gorgeu, CS 93837, 29238, Brest Cedex 08, France

    Christine Moisan

  3. Department of Molecular Biosciences Department – Programme for Physiology, University of Oslo, P.O. Box 1041, Blindern, 0371, Oslo, Norway

    Finn-Arne Weltzien

  4. Développement, Evolution et Plasticité du Système Nerveux, UPR CNRS 2197, Institut de Neurobiologie Alfred Fessard, CNRS, 91198, Gif-sur-Yvette Cedex, France

    Catherine Pasqualini

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  1. Marie-Emilie Sébert
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  2. Finn-Arne Weltzien
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Correspondence to Marie-Emilie Sébert.

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Guest editors: S. Dufour, E. Prévost, E. Rochard & P. Williot

Fish and diadromy in Europe (ecology, management, conservation)

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Sébert, ME., Weltzien, FA., Moisan, C. et al. Dopaminergic systems in the European eel: characterization, brain distribution, and potential role in migration and reproduction. Hydrobiologia 602, 27–46 (2008). https://doi.org/10.1007/s10750-008-9288-1

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