title: Uranium-induced sensory alterations in the zebrafish Danio rerio.
abstract: The effect of chronic exposure to uranium ions (UO(2)(2+)) on sensory tissues including the olfactory and lateral line systems was investigated in zebrafish (Danio rerio) using scanning electron microscopy. The aim of this study was to determine whether exposure to uranium damaged sensory tissues in fish. The fish were exposed to uranium at the concentration of 250 μg l(-1) for 10 days followed by a depuration period of 23 days. Measurements of uranium uptake in different fish organs: olfactory rosettes and bulbs, brain, skin, and muscles, were also determined by ICP-AES and ICP-MS during the entire experimental period. The results showed that uranium displayed a strong affinity for sensory structures in direct contact with the surrounding medium, such as the olfactory and lateral line systems distributed on the skin. A decreasing gradient of uranium concentration was found: olfactory rosettes>olfactory bulbs>skin>muscles>brain. At the end of the experiment, uranium was present in non-negligible quantities in sensory tissues. In parallel, fish exposed to uranium showed severe sensory tissue alterations at the level of the olfactory and lateral line systems. In both sensory systems, the gross morphology was altered and the sensory hair cells were significantly damaged very early after the initiation of exposure (from the 3rd day). At the end of the experiment, after 23 days of depuration, the lateral line system still displayed slight tissue alterations, but approximately 80% of the neuromasts in this system had regenerated. In contrast, the olfactory system took more time to recover, as more than half of the olfactory rosettes observed remained destroyed at the end of the experiment. This study showed, for the first time, that uranium is able to damage fish sensory tissues to such an extent that tissue regeneration is delayed.
authors.affiliation: Laboratoire d'écotoxicologie des radionucléides (LECO), Institut de Radioprotection et Sûreté Nucléaire, Centre de Cadarache, Saint Paul lez Durance, France. kfaucher@hotmail.fr
authors.forename: K
authors.initials: K
authors.lastname: Faucher
authors.forename: M
authors.initials: M
authors.lastname: Floriani
authors.forename: R
authors.initials: R
authors.lastname: Gilbin
authors.forename: C
authors.initials: C
authors.lastname: Adam-Guillermin
mesh_terms: D000818:Animals; D004781:Environmental Exposure; D053403:Lateral Line System / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D009833:Olfactory Pathways / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors; D014501:Uranium / Q000378:metabolism / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish / Q000378:metabolism / Q000502:physiology*
chemical_list: D014874:Water Pollutants, Chemical; D014501:Uranium