Raphe nucleus, in the brain stem is responisble for the secretion of which of the following chemicals?

Raphe nucleus is a cluster of cells found in the brain stem, their main function is to secrete serotonin. Serotonin (5-hydroxytryptamine; 5-HT) is present in highest concentration in blood platelets and in the gastrointestinal tract, where it is found in the enterochromaffi n cells and the myenteric plexus. Lesser amounts are found in the brain and in the retina. Ref: Molecular and Cellular Signalling By Main Beckerman, Page 292