Navegando por Autor "BONCI, Daniela Maria Oliveira"

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Acesso aberto (Open Access)
Losses of immunoreactive parvalbumin amacrine and immunoreactive alphaprotein kinase C bipolar cells caused by methylmercury chloride intoxication in the retina of the tropical fish Hoplias malabaricus
(2006-03) BONCI, Daniela Maria Oliveira; LIMA, Silene Maria Araújo de; GRÖTZNER, Sonia Regina; RIBEIRO, Ciro Alberto de Oliveira; HAMASSAKI, Dânia Emi; VENTURA, Dora Selma Fix
To quantify the effects of methylmercury (MeHg) on amacrine and on ON-bipolar cells in the retina, experiments were performed in MeHg-exposed groups of adult trahiras (Hoplias malabaricus) at two dose levels (2 and 6 µg/g, ip). The retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-aprotein kinase C (aPKC) immunocytochemistry. Morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (PV-IR) and aPKC (aPKC-IR) in wholemount preparations. Cell density, topography and isodensity maps were estimated using confocal images. PV-IR was detected in amacrine cells in the inner nuclear layer and in displaced amacrine cells from the ganglion cell layer, and aPKC-IR was detected in ON-bipolar cells. The MeHg-treated group (6 µg/g) showed significant reduction of the ON-bipolar aPKC-IR cell density (mean density = 1306 ± 393 cells/mm2) compared to control (1886 ± 892 cells/mm2; P < 0.001). The mean densities found for amacrine PV-IR cells in MeHg-treated retinas were 1040 ± 56 cells/mm2 (2 µg/g) and 845 ± 82 cells/mm2 (6 µg/g), also lower than control (1312 ± 31 cells/mm2; P < 0.05), differently from the data observed in displaced PV-IR amacrine cells. These results show that MeHg changed the PV-IR amacrine cell density in a dose-dependent way, and reduced the density of aKC-IR bipolar cells at the dose of 6 µg/g. Further studies are needed to identify the physiological impact of these findings on visual function.
Acesso aberto (Open Access)
The genetics of New World monkey visual pigments
(2013-07) BONCI, Daniela Maria Oliveira; NEITZ, Maureen; NEITZ, Jay; SILVEIRA, Luiz Carlos de Lima; VENTURA, Dora Selma Fix
To have color vision, having at least two cone photopigment types with different spectral sensitivities present in distinct photoreceptors is necessary together with the neural circuitry necessary to extract color information. Visual pigments are highly conserved molecules, but differences can be found among vertebrate groups. Primates have a variety of cone photopigments (i.e., opsins) that are expressed by polymorphic genes. This article examines the diversity of cone photopigments in New World monkeys and their behavioral relevance.