Dopamine is commonly associated with the pleasure system of the brain, providing feelings of enjoyment the experience of being in love, and reinforcement to motivate us to do certain activities. It also is critical to the way the brain controls movement (shortage of dopamine causes Parkinson's disease, for example).This 1 1/4" sterling silver pendant in the form of the dopamine molecule is stung on an 18" sterling snake chain and closes with a lobster clasp.It's packaged in a recycled gift box and an information tag about dopamine is included.