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. The virus has a long incubation period and sometimes won't show symptoms until 30 to 60 days after infection. Most often symptoms appear two weeks to 60 days after you've been infected.The most common symptom is constant fatigue, a constant state of feeling tired.verview. Mononucleosis is a respiratory virus that affects the blood cells and salivary glands (glands responsible for producing saliva). Even though anyone can get mononucleosis, most people who get the illness are between the ages of 15 and 25. Mono can keep you out of work or school for several weeks or months.