Brain Chemistry

A chemical called "dopamine" is broadly spread through the brain by specialized nerve cells, when a person achieves some kind of reward. Its chemical actions are produced also by closely related compounds such as amphetamine and cocaine. They give feelings of optimism, energy, power, and knowledge.

another chemical called "serotonin" is important in bringing mental relaxation as an important condition for getting to sleep. We don't really know yet what sleep is for, but we know that we can't survive without it.

Scientists have learned that, when animals mate and give birth, specialized chemicals are released into their brains that enable their behavior to change. Maternal and paternal patterns of nursing and caring appear. The most important is a chemical called "oxytocin". It doesn't cause joy. But it may cause anxiety, because it melts down the patterns of connections among neurons that hold experience, so that new experience can form. We become aware of this meltdown as a frightening loss of identity and self control, when we fall in love for the first time.