How is serotonin used by moods?

It is your Happy NT. The beauty of these neurotransmitters is they perform a variety of function leading to happiness, including your sleep, apetite , weight, regulation of anxiety even found in your gut cells, so happiness is not locatede in brain, remember, gut feeling, or irritable bowel when people are upset, brain and body are not disconnected and the brain is the most organic organ, connected to body happiness.