Physiological significance of melatonin and its precursor in mammals

为了阐明褪黑素的生理作用，我们培育了褪黑素熟练的N-乙酰五羟色胺(NAS；褪黑素的前身)熟练的和两者都缺乏的B6同源基因小鼠。我们检查了这些小鼠的昼夜节律相关行为，发现没有显著差异。此外，在这些小鼠的寿命中没有发现明显的差异。在行为分析中，我们在NAS小鼠身上发现了几个显著的差异，比如尾部悬挂实验中的不动时间较短，记忆保持能力较差。我们的免疫组织化学数据显示NAS小鼠的神经再生增强，这是可能的。

To clarify the physiological role of melatonin, we developed melatonin-proficient, N-acetylserotonin (NAS; a precursor of melatonin)-proficient, and both-deficient B6 congenic mice. We examined the circadian rhythm-related behaviors in these mice and found no significant difference. Further, there is no dramatic differences in the life span was found in these mice. In behavioral analysis, we detected several significant difference in NAS+ mice, in particular; such as short immobility time in the tail suspension test and worse memory retention. It is possible to be explained by our immunohistochemical data showing enhanced neurogenesis in NAS+ mice.