Methylmercury localization in Danio rerio retina after trophic and subchronic exposure: a basis for neurotoxicology.
Methylmercury is a known neurotoxic organometal which affects visual functions and few studies concerns to wild fish are available. The autometallography mercury distribution in the retina of Danio rerio was mapped using light and electron microscopy. Abundant mercury deposits were found in the photoreceptor layer (outer and inner segments of the photoreceptors) and in the inner and outer nuclear layers. Occasionally, the presence of mercury deposits in plexiform layers was observed and very rarely in the ganglion cell layer. Also the occurrence of mercury deposits in cells from the disc region was observed, but not in the nerve fiber layer. An interesting difference was found between mercury accumulation in the central and peripheral regions of the retina. These results demonstrate that mercury after trophic exposure to Danio rerio is able to cross the blood-retina barrier and accumulate in the cells of the retina even under subchronic exposure.
Mela
Maritana
M
Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, São Paulo, SP, Brazil. maritana.mela@gmail.com
Cambier
Sebastien
S
Mesmer-Dudons
Nathalie
N
Legeay
Alexia
A
Grötzner
Sonia Regina
SR
de Oliveira Ribeiro
Ciro Alberto
CA
Ventura
Dora Fix
DF
Massabuau
Jean-Charles
JC
D000818:Animals; D001813:Blood-Retinal Barrier / Q000187:drug effects; D008297:Male; D008628:Mercury / Q000378:metabolism*; D008767:Methylmercury Compounds / Q000494:pharmacology*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D009474:Neurons / Q000145:classification / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D012160:Retina / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D015027:Zebrafish / Q000033:anatomy & histology*
D008767:Methylmercury Compounds; D008628:Mercury