Wanting, or desire, flows from an evolutionarily old part of the brain deep inside the skull called the ventral tegmental area. It is rich in dopamine; in fact, it is one of the two main dopamine-producing regions. Like most brain cells, the cells that grow there have long tails that wind through the brain until they reach a place called the nucleus accumbens. When these long-tailed cells are activated, they release dopamine into the nucleus accumbens, driving the feeling we know as motivation. The scientific term for this circuit is the