Regional Specialisation of the Ganglion Cell Density in the Retina of the Native Duck (Anas platyrhynchos) of Bangladesh

Abstract

In this study, retinal whole-mount specimens were prepared and stained with 0.1% cresyl violet for the ganglion cell study in the native duck (Anas platyrhynchos). The total number, distribution and size of these cells were determined in different retinal regions. The mean total number of ganglion cells was 1 598 501. The retinal area centralis had the highest ganglion cell density with 11 200 cells/mm(2) . Number of ganglion cell bodies was the highest in temporal area, followed by dorsal, nasal and ventral areas. Ganglion cell size ranged from 5.25 to 80 μm(2) . In the temporal and nasal region, most of the cells were ranged from 15 to 25 μm(2) , and in the dorsal and ventral region, most of the cells were ranged from 12 to 25 μm(2) . There was a marked trend for the retinal ganglion cell size to increase as the population density decrease towards the periphery. A population of small ganglion cells persisted into the central area just above the optic disc and the largest soma area was in the ventral zone of the retina. Thus, the specialisation of ganglion cell densities and their sizes support the notion that the conduction of visual information towards the brain from all regions of the retina is not uniform, and the central area is the fine quality area for vision in native duck.