Cambras Trinitat, López Laudino, Arias Jorge Luis, Díez-Noguera Antoni
Department of Physiology, Faculty of Pharmacy, University of Barcelona, Barcelona, Spain.
Brain Res Dev Brain Res. 2005 Jun 9;157(1):27-33. doi: 10.1016/j.devbrainres.2005.02.014. Epub 2005 Apr 15.
To examine whether lighting conditions during the development of the rat circadian system affect the morphology of the suprachiasmatic nucleus (SCN), three groups of rats were born and maintained until they were 24 days old under constant light (LL), constant darkness (DD) or 24-h light-dark cycles (LD, 12-h light and 12-h darkness). We applied a stereological method to study whether these conditions lead to alterations in the volume of the SCN and changes in the total number of neurons and glial cells. While lighting conditions did not induce differences in the SCN volume, the number of both neurons and glial cells did differ between groups. The DD rats showed the lowest number of neurons. Glial cells were also lower in this group than in the other two groups; however the number of glial cells in LL rats was lower than in LD rats. Moreover, females had more glial cells than males but males and females showed a similar number of neurons. These findings indicate the plasticity of the SCN in response to lighting conditions during the developmental stage.
为研究大鼠昼夜节律系统发育过程中的光照条件是否会影响视交叉上核（SCN）的形态，将三组大鼠分别在持续光照（LL）、持续黑暗（DD）或24小时明暗循环（LD，12小时光照和12小时黑暗）条件下饲养至24日龄。我们采用体视学方法研究这些条件是否会导致SCN体积的改变以及神经元和神经胶质细胞总数的变化。虽然光照条件并未引起SCN体积的差异，但各组间神经元和神经胶质细胞的数量存在差异。DD组大鼠的神经元数量最少。该组的神经胶质细胞数量也低于其他两组；然而，LL组大鼠的神经胶质细胞数量低于LD组大鼠。此外，雌性大鼠的神经胶质细胞比雄性大鼠多，但雄性和雌性大鼠的神经元数量相似。这些发现表明，发育阶段的SCN对视光照条件具有可塑性。
