Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin and vitamin B3. It works by stimulating melatonin receptors and blocking serotonin receptors. The SCN regulates the pineal gland, which secretes the hormone melatonin. In response, the pineal secretes the hormone melatonin. Circadian rhythms and regulation of the hormone melatonin also seem to be altered. Studies in mice suggest that the pineal-derived melatonin regulates new bone deposition. This suppresses daytime melatonin, enabling wakefulness. The evidence for melatonin in treating insomnia is generally poor. They appear to have lost their pineal organ, but still show signs of melatonin rhythms. Positions on the benefits of melatonin for insomnia are mixed. RBD may be treated with melatonin or clonazepam. The secretion of melatonin happens in a cycle. Exogenous administration of melatonin was able to reduce inflammation. Second, inflammation may occur during sleep times due to the presence of melatonin. The expression patterns in melatonin receptors are unique.