Yoshikawa T, Yashiro Y, Oishi T, Kokame K, Fukada Y
Department of Biology, Faculty of Science, Nara Women's University, Japan.
Zoolog Sci. 1994 Oct;11(5):675-80.
Birds and lower vertebrates are known to have extra-retinal photoreceptors in the pineal complex and deep brain. Although the photoreceptive function of the pineal complex has been investigated well, the exact location and nature of the deep brain photoreceptors are not known. In this study we tried to localize visual pigments and signal transduction proteins immunohistochemically in the brain of bullfrogs (Rana catesbeiana). The retina, and the brain with the pineal and the frontal organ were fixed with Zamboni's fixative and/or Bouin's solution. Immunoreactivities to three antisera against bovine rhodopsin (Rh-As), alpha-subunits of bovine rod (anti-pTr alpha) and cone transducin (anti-pTc alpha) were shown in the retina, pineal, frontal organ and hypothalamus. The retina and pineal were immunopositive to both Rh-As and anti-pTr alpha, whereas the frontal organ was immunopositive to only Rh-As and the hypothalamus was immunopositive to all three antisera. The cells which were immunoreactive to Rh-As, anti-pTr alpha and anti-pTc alpha were observed in the preoptic nucleus and suprachiasmatic nucleus in the hypothalamus. The shape of these immunoreactive cells in the hypothalamus was round or spindle-like with one or two immunoreactive nerve processes most of which were perpendicular to the ventricular surface. Western blot analysis of the hypothalamus, pineal and frontal organ demonstrated immunoreactive bands molecular weight of which corresponded to those of the retina (34 kDa, 38 kDa and 41 kDa). Thus, visual pigments and transducin-like proteins seem to exist in the hypothalamus as well as the pineal complex of frogs.
已知鸟类和低等脊椎动物在松果体复合体和脑深部具有视网膜外光感受器。尽管松果体复合体的光感受功能已得到充分研究，但脑深部光感受器的确切位置和性质尚不清楚。在本研究中，我们试图通过免疫组织化学方法在牛蛙（Rana catesbeiana）脑中定位视觉色素和信号转导蛋白。视网膜以及带有松果体和额器官的脑用赞博尼固定液和/或布因氏溶液固定。针对牛视紫红质（Rh-As）、牛视杆细胞α亚基（抗-pTrα）和视锥转导蛋白α亚基（抗-pTcα）的三种抗血清的免疫反应性在视网膜、松果体、额器官和下丘脑均有显示。视网膜和松果体对Rh-As和抗-pTrα均呈免疫阳性，而额器官仅对Rh-As呈免疫阳性，下丘脑对所有三种抗血清均呈免疫阳性。在下丘脑的视前核和视交叉上核中观察到对Rh-As、抗-pTrα和抗-pTcα呈免疫反应性的细胞。下丘脑这些免疫反应性细胞的形状为圆形或纺锤形，有一或两个免疫反应性神经突起，其中大多数垂直于脑室表面。下丘脑、松果体和额器官的蛋白质免疫印迹分析显示免疫反应条带的分子量与视网膜的分子量（34 kDa、38 kDa和41 kDa）相对应。因此，视觉色素和转导蛋白样蛋白似乎不仅存在于青蛙的松果体复合体中，也存在于下丘脑中。
