The Hormone of Love

In William Shakespeare s day (1564-1616), there was wrangling about the relative importance of the heart or the brain as the seat of intelligence and emotions. He wrote, Tell me where is fancy bred in the heart or in the head.  

Oxytocin, as well as dopamine, norepinephrine, androgens, estrogens, and vasopressin, is related to the sex drive and sexual arousal, is secreted during sex, and is associated with feelings of love, altruism, warmth, calmness, bonding, tenderness, togetherness, and bodily contact. 

Secretion of oxytocin is regulated by the electrical activity of the neurons in the hypothalamus, which generate action potentials that propagate down axons to the nerve endings in the pituitary. These axons contain oxytocin-containing vesicles, which are released when the nerve terminals are depolarized. 

Serotonin also affects the emotions of love and romance. Androgens, estrogens, oxytocin, and vasopressin increase the sex drive, whereas increased levels of synaptic serotonin, such as result from the taking of reuptake transporter inhibitors, suppress the sex drive and inhibit feelings of attraction by the opposite sex. Dopamine and norepinephrine increase the sex drive. 

Helen Fisher of Rutgers University wrote, Everything that happens with romantic love has a chemical basis. She reports studies using functional magnetic resonance imaging 

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