ANATOMY

Detailed explanation-1: -Melatonin provides a circadian and seasonal signal to the organisms in vertebrates. Melatonin is produced from serotonin (made from tryptophan), through a cascade of enzymatic reactions (Figure 1).

Detailed explanation-2: -By identifying the release mechanism, cell signaling in the pinealocytes, and its effect on norepinephrine-induced melatonin secretion, our study defines serotonin as an autocrine neurotransmitter in the pineal gland and suggests possible modulatory targets for melatonin secretion.

Detailed explanation-3: -Pinealocytes synthesize the hormone melatonin by first converting the amino acid tryptophan to serotonin. The serotonin is then acetylated by the AANAT enzyme and converted into N-acetylserotonin.