 a micro drop of chemical that goes and touches the next nerve to send the impulse. There are three such chemicals in the brain. They're called neurotransmitters. One is norepinephrine or epinephrine or adrenaline. The other one is dopamine, which is the pleasure hormone. When you eat a pie or have sex, your dopamine is released. The third one is called happiness hormone, which is the serotonin. So when the serotonin is released,