What many people do not understand is that serotonin also plays a role in gastrointestinal disorders. In fact, the majority of our serotonin is produced in the gut, roughly 95%. Serotonin is produced in the enterochromaffin cells (EC) in the intestinal mucosa.Serotonin is produced, and then it bonds with its receptors.hat many people do not understand is that serotonin also plays a role in gastrointestinal disorders. In fact, the majority of our serotonin is produced in the gut, roughly 95%. Serotonin is produced in the enterochromaffin cells (EC) in the intestinal mucosa.
Early signs of mono in teens: 1  Early symptoms of viral infectious mono disease in teens are similar to flu symptoms. 2  Fever with shivering. 3  Teens may get headaches, severe fatigue, and pain in the muscles.  Sore throat with swollen tonsils, a common flu symptom, is also seen in mono.
Symptoms. Typical symptoms of infectious mononucleosis usually appear 4 to 6 weeks after you get infected with EBV. Symptoms may develop slowly and may not all occur at the same time. These symptoms includeâ. 1  extreme fatigue. 2  fever. 3  sore throat. 4  head and body aches.ymptoms. Typical symptoms of infectious mononucleosis usually appear 4 to 6 weeks after you get infected with EBV. Symptoms may develop slowly and may not all occur at the same time. These symptoms includeâ. 1  extreme fatigue. 2  fever. 3  sore throat. 4  head and body aches.