Definition: Serotonin is a neurotransmitter, or a chemical messenger that helps to relay messages from one brain cell to another. It is involved in sleep, appetite, sex as well as mood and anxiety modulation.
Serotonin - What is Serotonin
By Keath Low, About.com
Updated: August 14, 2008
About.com Health's Disease and Condition content is reviewed by the Medical Review Board
Explore ADD / ADHD
Must Reads
About.com Special Features
Learn how you can reduce your your numbers with these nutrition and exercise tips. More >
Keep yourself, and your family, happy and healthy this fall with these tips. More >
Also from About.com:
©2009 About.com, a part of The New York Times Company.
All rights reserved.