Dopamine is a neurotransmitter that is responsible for movement, motivation, and drive. It works by co-releasing glutamate, an excitatory neurotransmitter that stimulates neurons to be electrically active. Dopamine stimulates action in general, making certain neurons more active, and tends to stimulate sympathetic arousal, increasing alertness and readiness to pursue things outside oneself. Dopamine is a universal currency in all mammals, including humans, for moving us toward goals. Dopamine can be released locally or broadly, and increasing dopamine levels can influence both local and volumetric release. However, increasing dopamine levels alone does not necessarily lead to sustained dopamine release over long periods of time. The dopamine system also interacts with the visual system, and when we use our visual system to focus on a particular point, it recruits chemical and neural systems in our brain and body that put us into a state of readiness and pursuit.