A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia.
J Anat. 2021 Apr;238(4):905-916. doi: 10.1111/joa.13346. Epub 2020 Oct 20.
Vision plays a crucial role in the life of the vast majority of vertebrate species. The spatial arrangement of retinal ganglion cells has been reported to be related to a species' visual behavior. There are many studies focusing on the ganglion cell topography in bony fish species. However, there are still large gaps in our knowledge on the subject. We studied the topography of retinal ganglion cells (GCs) in the Japanese smelt Hypomesus nipponensis, a highly visual teleostean fish with a complex life cycle. DAPI labeling was used to visualize cell nuclei in the ganglion cell and inner plexiform layers. The ganglion cell layer was relatively thin (about 6-8 μm), even in areas of increased cell density (area retinae temporalis), and was normally composed of a single layer of cells. In all retinal regions, rare cells occurred in the inner plexiform layer. Nissl-stained retinae were used to estimate the proportion of displaced amacrine cells and glia in different retinal regions. In all retinal regions, about 84.5% of cells in the GC layer were found to be ganglion cells. The density of GCs varied across the retina in a regular way. It was minimum (3990 and 2380 cells/mm in the smaller and larger fish, respectively) in the dorsal and ventral periphery. It gradually increased centripetally and reached a maximum of 14,275 and 10,960 cells/mm (in the smaller and larger fish, respectively) in the temporal retina, where a pronounced area retinae temporalis was detected. The total number of GCs varied from 177 × 10 (smaller fish) to 212 × 10 cells (larger fish). The theoretical anatomical spatial resolution (the anatomical estimate of the upper limit of visual acuity calculated from the density of GCs and eye geometry and expressed in cycles per degree) was minimum in the ventral periphery (smaller fish, 1.46 cpd; larger fish, 1.26 cpd) and maximum in area retinae temporalis (smaller fish, 2.83 cpd; larger fish, 2.75 cpd). The relatively high density of GCs and the presence of area retinae temporalis in the Japanese smelt are consistent with its highly visual behavior. The present findings contribute to our understanding of the factors affecting the topography of retinal ganglion cells and visual acuity in fish.
视觉在绝大多数脊椎动物的生活中起着至关重要的作用。视网膜神经节细胞的空间排列与物种的视觉行为有关。有许多研究专注于骨鱼物种的神经节细胞拓扑结构。然而，我们在这方面的知识仍然存在很大的差距。我们研究了日本鱵 Hypomesus nipponensis 的视网膜神经节细胞 (GC) 的拓扑结构，这是一种具有复杂生命周期的高度视觉的硬骨鱼。DAPI 标记用于显示神经节细胞和内丛状层中的细胞核。神经节细胞层相对较薄（约 6-8μm），即使在细胞密度增加的区域（颞视网膜区）也是如此，并且通常由单层细胞组成。在内丛状层中偶尔会出现少量细胞。用尼氏染色的视网膜用于估计不同视网膜区域中迁移性无长突细胞和神经胶质的比例。在所有视网膜区域中，GC 层中的约 84.5%的细胞被发现是神经节细胞。GC 的密度在视网膜上以规则的方式变化。在背侧和腹侧外围最小（小鱼和大鱼中分别为 3990 和 2380 个细胞/mm）。它向中心逐渐增加，并在颞视网膜处达到最大值 14275 和 10960 个细胞/mm（小鱼和大鱼中分别），在那里检测到明显的颞视网膜区。GC 的总数从 177×10（小鱼）到 212×10 个细胞（大鱼）不等。理论解剖空间分辨率（从 GC 密度和眼睛几何形状计算得出的视觉锐度的上限的解剖估计值，并以每度的周期表示）在腹侧外围最小（小鱼，1.46cpd；大鱼，1.26 cpd），在颞视网膜区最大（小鱼，2.83 cpd；大鱼，2.75 cpd）。日本鱵的 GC 密度较高和颞视网膜区的存在与其高度的视觉行为一致。本研究结果有助于我们了解影响鱼类视网膜神经节细胞和视觉锐度的因素。
