Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashiosaka 5778502, Japan.
Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashiosaka 5778502, Japan.
Gen Comp Endocrinol. 2023 Nov 1;343:114355. doi: 10.1016/j.ygcen.2023.114355. Epub 2023 Aug 8.
The neurohypophysial peptide arginine vasotocin (VT) and its mammalian ortholog, arginine vasopressin, function in physiological and behavioral events. These functions have been identified in neuroendocrinological studies using adult animals; however, there is little information on whether VT is associated with social behavior development in fish. Here, we examined social preference in medaka fish of various ages and investigated how VT expression changes during development. The 1-, 2-, 4-, and 8-week post-hatching (wph) larvae, juveniles, and 5-month-old adults were individually introduced to the grouped fish of each age group, and the social preference index (SPI) was compared among ages based on the time spent in the interaction zone near the grouped fish in a test tank. The SPI was significantly higher in the 4-wph larvae, 8-wph juveniles, and adult fish than in the 1- and 2-wph larvae. VT expression increased with age from 1 to 4 wph. Similarly, the expression was high in 4-wph, 8-wph, and adult fish. Furthermore, it was also found that the SPI and the VT expression decreased in the socially isolated larva during the 4 weeks after hatching compared to the levels in the grouped 4-wph larvae. These findings suggest that social preference develops with age and that conspecifics are necessary for social development in medaka larvae. Furthermore, our results suggest that VT is associated with the development of social preferences in medaka.
神经垂体肽精氨酸血管加压素 (VT)及其哺乳动物同源物精氨酸血管升压素在生理和行为事件中发挥作用。这些功能已在使用成年动物的神经内分泌研究中得到确定；然而，关于 VT 是否与鱼类的社交行为发展有关的信息很少。在这里，我们检查了各种年龄的斑马鱼的社交偏好，并研究了 VT 表达在发育过程中的变化。将 1、2、4 和 8 周孵化后（wph）的幼虫、幼鱼和 5 个月大的成鱼分别引入每个年龄组的成群鱼类中，并根据在测试罐中靠近成群鱼类的互动区域花费的时间，比较了不同年龄之间的社交偏好指数 (SPI)。4wph 幼虫、8wph 幼鱼和成鱼的 SPI 明显高于 1wph 和 2wph 幼虫。VT 表达从 1 到 4 wph 随着年龄的增长而增加。同样，4wph、8wph 和成年鱼中的表达也很高。此外，还发现与成群的 4wph 幼虫相比，在孵化后 4 周内，单独饲养的幼虫的 SPI 和 VT 表达降低。这些发现表明社交偏好随年龄发展，并且同种鱼类对于斑马鱼幼虫的社交发展是必要的。此外，我们的结果表明，VT 与斑马鱼社交偏好的发展有关。
