This free PowerPoint template is of a serotonin molecule. This molecule is something called a neurotransmitter, a chemical which signals changes within the brain and spinal cord. It is also present in nerves all over the body. Serotonin is the old name for the molecule, 5-HT (5-hydroxytryptamine), but is used more frequently in scientific literature. Within this PowerPoint template, there are three different types of molecular representations. On the second slide is the skeletal formula.