Neurotransmitters Necklace. This wonderful necklace is comprised of the molecules Dopamine, Serotonin, and Acetylcholine. Together, these are the neurotransmitters that help us feel joy, happiness, and love. The necklace is made from lead-free, nickel-free zinc alloy, separated by non-tarnishing steel beads. They are hand-strung on an 18 inch non-tarnishing steel snake chain.