A study of pupil in Medaka

教科书上说，大多数硬骨鱼类的虹膜大小不会改变，尽管包括软骨鱼纲在内的所有脊椎动物都会在自主神经系统的控制下改变虹膜的大小，以响应强光。本研究采用高分辨率数字图像记录和图像分析技术，对模式硬骨鱼青鳉（Oryzias latipes）虹膜的大小变化进行了细致的研究。在强光照射下，青鳉的瞳孔缩小，出现瞳孔缩小。此外，通过施用乙酰胆碱或坦索罗辛激活副交感神经系统活性诱导瞳孔缩小，强烈表明青鳉的虹膜收缩与人类的方式相同，通过自主神经系统的控制。阿托品或苯肾上腺素的管理没有增加瞳孔的大小，这表明虹膜的检查个人扩大最大可能是因为交感神经活动被彻底激活拍照。

Textbooks say that the iris size does not change in most species of teleost, although all vertebrates including Chondrichthyes change the size of iris in response to strong light under control by autonomic nervous system. In this study, employing high-resolution digital image recording and image analysis the size change of iris was examined carefully in a model teleost, medaka (Oryzias latipes). When exposed to strong light, medaka decreased the size of pupil, showing miosis. Moreover, activation of parasympathetic nervous system activity by administration of acetylcholine or tamsulosin induced miosis, strongly suggesting that iris contracts via control by autonomic nervous system in medaka as the same manner as human. Administration of atropine or phenylephrine did not increase the size of pupil, suggesting that the iris of the examined individual expanded maximum presumably because sympathetic nervous activity was thoroughly activated by taking pictures.