Dopamine as the dependent variable

Dopamine as the dependent variable discusses how postmortem biochemistry, intracerebral microdialysis, electrophysiological recording, in vivo electrochemistry, and positron emission tomography studies provide compelling evidence that dopaminergic neurons are activated by primary rewarding stimuli including food and water and by numerous conditioned incentives, including money. Early in training, primary rewarding stimuli activate dopaminergic neurons. When a cue is reliably paired with a primary rewarding stimulus over trials, the dopamine response begins to be seen upon presentation of the cue and eventually is not seen upon presentation of the primary rewarding stimulus when it follows the cue. These conditioned cues acquire the ability to act as rewarding stimuli that can produce incentive learning. If conditioned incentive stimuli are repeatedly presented in the absence of primary incentive stimuli, they gradually lose their ability to elicit approach and other responses and to act as rewarding stimuli by producing incentive learning in their own right.