Photoreceptor types and distributions in the retinae of insectivores.

Details

Serval ID
serval:BIB_D4C6762A5065
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Photoreceptor types and distributions in the retinae of insectivores.
Journal
Visual Neuroscience
Author(s)
Peichl L., Künzle H., Vogel P.
ISSN
0952-5238 (Print)
ISSN-L
0952-5238
Publication state
Published
Issued date
2000
Peer-reviewed
Oui
Volume
17
Number
6
Pages
937-948
Language
english
Abstract
The retinae of insectivores have been rarely studied, and their photoreceptor arrangements and expression patterns of visual pigments are largely unknown. We have determined the presence and distribution of cones in three species of shrews (common shrew Sorex araneus, greater white-toothed shrew Crocidura russula, dark forest shrew Crocidura poensis; Soricidae) and in the lesser hedgehog tenrec Echinops telfairi (Tenrecidae). Special cone types were identified and quantified in flattened whole retinae by antisera/antibodies recognizing the middle-to-long-wavelength-sensitive (M/L-)cone opsin and the short-wavelength-sensitive (S-)cone opsin, respectively. A combination of immunocytochemistry with conventional histology was used to assess rod densities and cone/rod ratios. In all four species the rods dominate at densities of about 230,000-260,000/mm2. M/L- and S-cones are present, comprising between 2% of the photoreceptors in the nocturnal Echinops telfairi and 13% in Sorex araneus that has equal diurnal and nocturnal activity phases. This suggests dichromatic color vision like in many other mammals. A striking feature in all four species are dramatically higher S-cone proportions in ventral than in dorsal retina (0.5% vs. 2.5-12% in Sorex, 5-15% vs. 30-45% in Crocidura poensis, 3-12% vs. 20-50% in Crocidura russula, 10-30% vs. 40-70% in Echinops). The functional and comparative aspects of these structural findings are discussed.
Keywords
Animals, Cell Count, Eye/anatomy & histology, Insectivora/anatomy & histology, Photoreceptor Cells, Vertebrate/classification, Photoreceptor Cells, Vertebrate/cytology, Retina/cytology, Retinal Cone Photoreceptor Cells/cytology, Retinal Cone Photoreceptor Cells/metabolism, Retinal Pigments/metabolism, Retinal Rod Photoreceptor Cells/cytology, Shrews/anatomy & histology
Pubmed
Web of science
Create date
24/01/2008 17:32
Last modification date
20/08/2019 15:54
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