How does a single chemical do both things? Think of rocket fuel that powers the main engines of a spaceship. The same fuel that pushes the rocket forward can be redirected to drive directional thrusters to steer the ship, as well as retrorockets to slow it down. It all depends on the path the fuel takes before it’s ignited—different functions, but all working together to get the spaceship to its destination. In a similar way, dopamine moving through different brain circuits yields different functions, too, and toward a common end: a relentless focus on enhancing the future.
