Retinal ganglion cell topography and spatial resolving power in the white rhinoceros (Ceratotherium simum)
| Autor: | João Paulo Coimbra, Paul R. Manger |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Black rhinoceros biology Ceratotherium simum General Neuroscience Streak Rhinoceros Retinal Anatomy biology.organism_classification Retinal ganglion Ganglion 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology 0302 clinical medicine medicine.anatomical_structure Retinal ganglion cell chemistry medicine 030217 neurology & neurosurgery |
| Zdroj: | Journal of Comparative Neurology. 525:2484-2498 |
| ISSN: | 0021-9967 |
| DOI: | 10.1002/cne.24136 |
| Popis: | This study sought to determine whether the retinal organization of the white rhinoceros (Ceratotherium simum), a large African herbivore with lips specialized for grazing in open savannahs, relates to its foraging ecology and habitat. Using stereology and retinal wholemounts, we estimated a total of 353,000 retinal ganglion cells. Their density distribution reveals an unusual topographic organization of a temporal (2,000 cells/mm2 ) and a nasal (1,800 cells/mm2 ) area embedded within a well-defined horizontal visual streak (800 cells/mm2 ), which is remarkably similar to the retinal organization in the black rhinoceros. Alpha ganglion cells comprise 3.5% (12,300) of the total population of ganglion cells and show a similar distribution pattern with maximum densities also occurring in the temporal (44 cells/mm2 ) and nasal (40 cells/mm2 ) areas. We found higher proportions of alpha cells in the dorsal and ventral retinas. Given their role in the detection of brisk transient stimuli, these higher proportions may facilitate the detection of approaching objects from the front and behind while grazing with the head at 45 °. Using ganglion cell peak density and eye size (29 mm, axial length), we estimated upper limits of spatial resolving power of 7 cycles/deg (temporal area), 6.6 cycles/deg (nasal area), and 4.4 cycles/deg (horizontal streak). The resolution of the temporal area potentially assists with grazing, while the resolution of the streak may be used for panoramic surveillance of the horizon. The nasal area may assist with detection of approaching objects from behind, potentially representing an adaptation compensating for limited neck and head mobility. J. Comp. Neurol., 525:2484-2498, 2017. © 2017 Wiley Periodicals, Inc. |
| Databáze: | OpenAIRE |
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