Mass Alla M, Supin A Y
Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
Brain Behav Evol. 2010;76(2):144-53. doi: 10.1159/000320951. Epub 2010 Nov 15.
Retinal topography, cell density and sizes of ganglion cells in the Caspian seal (Pusa caspica) were analyzed in retinal whole mounts stained with cresyl-violet. The topographic distribution of ganglion cells displayed an area of high cell density located in the temporal quadrant of the retina and was similar to the area centralis of terrestrial carnivores. It extended nasally, above the optic disk, as a streak of increased cell density. In different whole mounts, the peak cell density in the high-density area ranged from 1,684 to 1,844 cells/mm² (mean 1,773 cells/mm²). The cell density data predict a retinal resolution of around 8.5 cycles/degree in water. A distinctive feature of the Caspian seal's retina is the large size of ganglion cells and the low cell density compared to terrestrial mammals. The ganglion cell diameter ranged from 10 to 58 μm. Cell size histograms featured bimodal patterns with groups of small and large ganglion cells. The large cells appeared similar to α-cells of terrestrial mammals and constituted 7% of the total ganglion cell population.
在用甲酚紫染色的视网膜整装片中，分析了里海海豹（Pusa caspica）的视网膜地形图、神经节细胞密度和大小。神经节细胞的地形分布显示，在视网膜颞侧象限有一个高细胞密度区域，类似于陆生食肉动物的中央凹区域。它在鼻侧延伸，在视盘上方，形成一条细胞密度增加的条纹。在不同的整装片中，高密度区域的峰值细胞密度范围为1684至1844个细胞/mm²（平均1773个细胞/mm²）。细胞密度数据预测在水中视网膜分辨率约为8.5周/度。与陆生哺乳动物相比，里海海豹视网膜的一个显著特征是神经节细胞大且细胞密度低。神经节细胞直径范围为10至58μm。细胞大小直方图呈现双峰模式，有小神经节细胞和大神经节细胞群体。大细胞看起来类似于陆生哺乳动物的α细胞，占神经节细胞总数的7%。
