The red fox (Vulpes vulpes) is the carnivore with the widest distribution in the world. Not much is known about the visual system of these predominantly forest-dwelling animals. The closely related Arctic fox (Vulpes lagopus) lives in more open tundra habitats. In search for corresponding adaptations, we examined the photoreceptors and retinal ganglion cells (RGCs), using opsin immunohistochemistry, lucifer yellow injections and Nissl staining. Both species possess a majority of middle-to-longwave-sensitive (M/L) and a minority of shortwave-sensitive (S) cones, indicating dichromatic color vision. Area centralis peak cone densities are 22,600/mm2 in the red fox and 44,800/mm2 in the Arctic fox. Both have a centro-peripheral density decrease of M/L cones, and a dorsoventrally increasing density of S cones. Rod densities and rod/cone ratios are higher in the red fox than the Arctic fox. Both species possess the carnivore-typical alpha and beta RGCs. The RGC topography shows a centro-peripheral density gradient with a distinct area centralis (mean peak density 7,900 RGCs/mm2 in the red fox and 10,000 RGCs/mm2 in the Arctic fox), a prominent visual streak of higher RGC densities in the Arctic fox, and a moderate visual streak in the red fox. Visual acuity and estimated sound localization ability were nearly identical between both species. In summary, the red fox retina shows adaptations to nocturnal activity in a forest habitat, while the Arctic fox retina is better adapted to higher light levels in the open tundra.

• MeSH
• čípky retiny fyziologie   MeSH
• druhová specificita MeSH
• fotoreceptory obratlovců fyziologie   MeSH
• imunohistochemie MeSH
• lišky fyziologie   MeSH
• lokalizace zvuku fyziologie   MeSH
• oči anatomie a histologie   MeSH
• opsiny metabolismus   MeSH
• retinální gangliové buňky fyziologie   MeSH
• tyčinky retiny fyziologie   MeSH
• vidění barevné fyziologie   MeSH
• životní prostředí MeSH
• zraková ostrost fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Cryptochromes are a ubiquitous group of blue-light absorbing flavoproteins that in the mammalian retina have an important role in the circadian clock. In birds, cryptochrome 1a (Cry1a), localized in the UV/violet-sensitive S1 cone photoreceptors, is proposed to be the retinal receptor molecule of the light-dependent magnetic compass. The retinal localization of mammalian Cry1, homologue to avian Cry1a, is unknown, and it is open whether mammalian Cry1 is also involved in magnetic field sensing. To constrain the possible role of retinal Cry1, we immunohistochemically analysed 90 mammalian species across 48 families in 16 orders, using an antiserum against the Cry1 C-terminus that in birds labels only the photo-activated conformation. In the Carnivora families Canidae, Mustelidae and Ursidae, and in some Primates, Cry1 was consistently labeled in the outer segment of the shortwave-sensitive S1 cones. This finding would be compatible with a magnetoreceptive function of Cry1 in these taxa. In all other taxa, Cry1 was not detected by the antiserum that likely also in mammals labels the photo-activated conformation, although Western blots showed Cry1 in mouse retinal cell nuclei. We speculate that in the mouse and the other negative-tested mammals Cry1 is involved in circadian functions as a non-light-responsive protein.

• MeSH
• antisérum chemie   MeSH
• Canidae fyziologie   MeSH
• čípky retiny - opsiny genetika   MeSH
• čípky retiny fyziologie   účinky záření   ultrastruktura   MeSH
• cirkadiánní rytmus fyziologie   účinky záření   MeSH
• exprese genu MeSH
• fylogeneze * MeSH
• Hominidae fyziologie   MeSH
• imunohistochemie MeSH
• konformace proteinů MeSH
• kryptochromy chemie   genetika   MeSH
• magnetické pole MeSH
• medvědovití fyziologie   MeSH
• Mustelidae fyziologie   MeSH
• proteinové domény MeSH
• ptáci fyziologie   MeSH
• savci klasifikace   fyziologie   MeSH
• světlo MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE: Several methods are routinely used in the clinic to diagnose and monitor diseases of inner retinal function. In this study, we compare four such methods in patients with diabetes and glaucoma, to determine correlations between their results and to determine which method is most sensitive for detecting disease. METHODS: Twenty control subjects, 12 patients with early glaucoma and eight patients with diabetes mellitus, were enrolled in the study. All underwent four examinations: transient pattern electroretinogram (PERG), multifocal pattern electroretinogram (mfPERG), chromatic contrast threshold measurements (protan and tritan), and blue-on-yellow short-wavelength automated perimetry (SWAP). RESULTS: For the total cohort of 40 subjects, the results show a significant correlation between the amplitudes of the PERG and those of the mfPERG, as well as between the tritan contrast thresholds and the SWAP MD. Furthermore, ROC analyses reveal that colour contrast thresholds could significantly distinguish between the patient and the control group. Glaucoma patients alone could also be distinguished. CONCLUSIONS: We conclude that the methods compared in this study show correlations between their results if they are testing same pathway or underling cells, and that the colour contrast threshold is the most sensitive method to detect early functional deficits in diabetic and glaucoma patients.

• MeSH
• čípky retiny fyziologie   MeSH
• citlivost na kontrast fyziologie   MeSH
• diabetes mellitus 1. typu diagnóza   patofyziologie   MeSH
• diabetická retinopatie diagnóza   patofyziologie   MeSH
• dospělí MeSH
• elektrofyziologické jevy MeSH
• elektrofyziologie metody   MeSH
• elektroretinografie metody   MeSH
• glaukom diagnóza   patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• poruchy barevného vidění diagnóza   patofyziologie   MeSH
• ROC křivka MeSH
• senioři MeSH
• senzorické prahy MeSH
• testy zrakového pole MeSH
• zraková pole fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

• MeSH
• biofyzikální jevy MeSH
• čípky retiny fyziologie   MeSH
• lidé MeSH
• luminiscenční měření MeSH
• obraz následný MeSH
• retinální gangliové buňky fyziologie   MeSH
• světelná stimulace MeSH
• vnímání barev MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

• Klíčová slova
• trichromatické vidění,
• MeSH
• biologická evoluce MeSH
• čípky retiny fyziologie   MeSH
• lidé MeSH
• nervový systém - fyziologické jevy MeSH
• primáti * MeSH
• retina fyziologie   MeSH
• vidění barevné * fyziologie   genetika   MeSH
• vnímání barev fyziologie   MeSH
• výzkum MeSH
• zraková percepce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH