Immunohistochemical characterization of a parapinopsin-containing photoreceptor cell involved in the ultraviolet/green discrimination in the pineal organ of the river lamprey Lethenteron japonicum
Immunohistochemical characterization of a parapinopsin-containing photoreceptor cell involved in the ultraviolet/green discrimination in the pineal organ of the river lamprey Lethenteron japonicum
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DOI：
10.1242/jeb.007161
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发表时间：
2007-11-01
影响因子：
2.8
通讯作者：
Tamotsu, Satoshi
中科院分区：
文献类型：
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作者：
Kawano-Yamashita, Emi;Terakita, Akihisa;Tamotsu, Satoshi
在松果体中，两种类型的神经节细胞对紫外光和绿色光表现出拮抗的色反应，对可见光表现出无色反应。在这项研究中，我们的组织学特征的紫外线敏感的感光细胞，含有一个独特的非视觉紫外线色素，七鳃鳗视蛋白，以阐明与拮抗色反应的神经网络。这些特性进行了比较与七鳃鳗视紫红质含细胞，其中大部分是参与无色反应。RT-PCR分析表明，七鳃鳗视蛋白的表达在松果体器官，但不是在视网膜，不像七鳃鳗视紫红质，这是在两者都表示。七鳃鳗视紫红质和副视紫红质分别定位于松果体的背侧和腹侧区域。这两种色素被定位在不同的感光细胞在整个松果体器官，即背侧和腹侧区域以及周边区域，这对应于背腹侧边界区域。周边区域的七鳃鳗视紫红质细胞的数量比周围的七鳃鳗视紫红质细胞的数量比中心区域的高。电子显微镜分析显示，七鳃鳗背侧含视后蛋白的细胞有类似的腹侧感光细胞的外节和突触带。然而，与七鳃鳗视紫红质含有细胞，七鳃鳗parapinopsin含有细胞相互连接在一个广泛的区域的背部和外周部分，并直接接触神经节细胞，主要是在外周部分。这些结果表明，紫外光的信息捕获七鳃鳗的parapinopsin含有感光细胞收敛，并直接传输到染色型神经节细胞在外周区域产生拮抗色反应。
In the pineal organ, two types of ganglion cell exhibit antagonistic chromatic responses to UV and green light, and achromatic responses to visible light. In this study, we histologically characterized UV-sensitive photoreceptor cells that contain a unique non-visual UV pigment, lamprey parapinopsin, in order to elucidate the neural network that is associated with antagonistic chromatic responses. These characteristics were compared with those of lamprey rhodopsin-containing cells, most of which are involved in achromatic responses. RT-PCR analysis revealed that lamprey parapinopsin was expressed in the pineal organ but not in the retina, unlike lamprey rhodopsin, which was expressed in both. Lamprey parapinopsin and lamprey rhodopsin were immunohistochemically localized in the dorsal and ventral regions of the pineal organ, respectively. The two pigments were localized in distinct photoreceptor cells throughout the pineal organ, namely the dorsal and ventral regions as well as the peripheral region, which corresponds to the dorso-ventral border region. The ratio of the number of lamprey parapinopsin-containing cells to lamprey rhodopsin-containing cells around the peripheral region was higher than in the central region. Electron-microscopic analysis revealed that lamprey parapinopsin-containing dorsal cells have outer segments and synaptic ribbons similar to those of ventral photoreceptor cells. However, unlike lamprey rhodopsin-containing cells, lamprey parapinopsin-containing cells connected with each other in a wide area of dorsal and peripheral portions and made direct contact with ganglion cells, mainly in the peripheral portion. These results suggest that UV light information captured by lamprey parapinopsin-containing photoreceptor cells is converged and directly transmitted to chromatic-type ganglion cells in the peripheral region to generate antagonistic chromatic responses.