Retinal cone photoreceptor distribution in the American black bear ( Ursus americanus )
| Autor: | Benjamin D. Reynolds, Kate E. Archibald, Melanie L. Foster, Freya M. Mowat, Jennifer L. Heyward, Michael K. Stoskopf |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Histology genetic structures Color vision Zoology Biology Retinal Cone Photoreceptor Cells Retina 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine biology.animal medicine Animals Carnivore Ursus Vision Ocular Ecology Evolution Behavior and Systematics Retinal biology.organism_classification eye diseases 030104 developmental biology medicine.anatomical_structure chemistry Optic nerve sense organs Anatomy American black bear Ursidae 030217 neurology & neurosurgery Biotechnology |
| Zdroj: | The Anatomical Record. 304:662-672 |
| ISSN: | 1932-8494 1932-8486 |
| Popis: | The distribution of cone photoreceptor subtypes (important for color vision and vision quality) varies widely in different carnivore species, but there have been limited studies on bear (ursid) cone distribution. A previous behavioral study suggests that American black bears (Ursus americanus) are dichromatic, indicating that they possess two cone subtypes, although the retinal distribution of cones is unknown. The purpose of this study was to examine the subtype and topography of cones in American black bear retinas to further predict the nature of their color vision and image resolution. We studied 10 eyes from seven individual legally hunted black bears in northeastern North Carolina. Cryosections and retinal wholemounts were labeled using antibodies targeting two cone opsin subtypes: long/medium (L/M) wavelength sensitive and short (S) wavelength sensitive. Cones in fluorescent microscopy images were counted and density maps were created for retinal wholemounts. The black bear retina contains both cone subtypes and L/M cones outnumber S cones by at least 3:1, a finding confirmed in retinal frozen sections. There are higher concentrations of S cones present than typically seen in other carnivores with some evidence for co-expression of L/M and S cones. A cone-dense area centralis is present dorsotemporal to the optic nerve, similar to other carnivores. These results confirm that American black bears are predicted to have a dichromatic vision with high acuity indicated by the presence of a dorsotemporally located area centralis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text