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.
The characteristic symptoms of infection with EBV include fever, fatigue, malaise, and sore throat. The designation  mononucleosis  refers to an increase in a particular type of mononuclear white blood cells (lymphocytes) in the bloodstream relative to the other white blood cells as a result of the EBV infection. The symptoms of mono include: 2  fever, 3  fatigue, 4  sore throat, and. 5  swollen lymph nodes. 6  The diagnosis of mono is confirmed by blood tests.