Figure 1
Schematic representation of the two serotonin systems in vertebrates. The top part denotes the process of serotonin biosynthesis, which is also the first two steps in melatonin synthesis. The middle part (in the circles) summarizes the functions regulated by the two serotonin systems. The bottom part interprets the last two steps for melatonin synthesis. 5-HT, 5-hydroxytryptamine; AAAD (AADC), |