Laboratory of Physiology, National Scientific Center of Marine Biology , Far Eastern Branch Russian Academy of Sciences, Vladivostok, Russia.
J Anat. 2019 Dec;235(6):1114-1124. doi: 10.1111/joa.13075. Epub 2019 Aug 16.
Tree frogs are an interesting and diverse group of frogs. They display a number of unique adaptations to life in the arboreal environment. Vision plays a crucial role in their ecology. The topography of retinal ganglion cells (GCs) is closely related to a species' visual behavior. Despite a large amount of research addressing GC topography in vertebrates, there is scarce data on this subject in tree frogs. I studied the topography of GCs in the retina of the Japanese tree frog Hyla japonica. The GC density distribution was locally fairly homogeneous, with spatial density increasing gradually from the dorsal and ventral periphery towards the equator. A moderately pronounced visual streak was found close to the equator in the dorsal hemiretina, with a distinct area retinae temporalis in the dorsotemporal quadrant potentially subserving binocular vision. The minimum GC density (mean ± SEM, n = 5) was 3060 ± 60 and the maximum 12 800 ± 170 cells/mm . The total number of GCs was 292 ± 7 × 10 . The theoretical anatomical spatial resolution estimated from GC densities and eye optics was lowest in the ventral periphery (ca. 0.9 and 1.3 cycles/degree in air and water, respectively) and highest in the area retinae temporalis (ca. 2.1 and 2.8 cycles/degree). The relatively high GC density and presence of specialized retinal regions in Hyla japonica are consistent with its highly visual behavior. The present findings contribute to our understanding of the relative role of common ancestry and environmental pressure in GC topography variation within Anura.
树蛙是一类有趣且多样的蛙类。它们展示了许多适应树栖环境的独特特征。视觉在它们的生态中起着至关重要的作用。视网膜神经节细胞（GC）的拓扑结构与物种的视觉行为密切相关。尽管有大量研究针对脊椎动物的 GC 拓扑结构，但关于树蛙的这方面数据却很少。我研究了日本树蛙（Hyla japonica）视网膜中 GC 的拓扑结构。GC 的密度分布在局部相当均匀，从背侧和腹侧的外周逐渐向赤道增加。在背侧半视网膜的赤道附近发现了一条中等程度明显的视觉纹，在背侧颞象限有一个明显的颞视网膜区域，可能用于双眼视觉。最小的 GC 密度（平均值 ± SEM，n = 5）为 3060 ± 60，最大为 12 800 ± 170 个细胞/mm 。GC 的总数为 292 ± 7 × 10 。从 GC 密度和眼部光学估计的理论解剖空间分辨率在腹侧外周最低（空气中约为 0.9 和 1.3 个周期/度，水中约为 2.1 和 2.8 个周期/度），在颞视网膜区域最高。日本树蛙中相对较高的 GC 密度和特化的视网膜区域的存在与其高度视觉行为一致。本研究结果有助于我们理解共同祖先和环境压力在蛙目 GC 拓扑结构变化中的相对作用。
