《Dopamine》.pdf

REVIEWS DOPAMINE, LEARNING AND MOTIVATION Roy A. Wise The hypothesis that dopamine is important for reward has been proposed in a number of forms, each of which has been challenged. Normally, rewarding stimuli such as food, water, lateral hypothalamic brain stimulation and several drugs of abuse become ineffective as rewards in animals given performance-sparing doses of dopamine antagonists. Dopamine release in the nucleus accumbens has been linked to the efficacy of these unconditioned rewards, but dopamine release in a broader range of structures is implicated in the ‘stamping-in’ of memory that attaches motivational importance to otherwise neutral environmental stimuli. NEUROLEPTIC The neurotransmitter dopamine — particularly Multiple dopamine hypotheses A drug that blocks the effects of nigrostriatal dopamine (BOX 1) — has long been identi- Dopamine was first identified with motivational func- dopamine by binding to and fied with motor function1. However, moderate doses of tion on the strength of Ungerstedt’s18 report that feeding occluding the dopamine NEUROLEPTIC drugs (dopamine antagonists) attenuate the and drinking deficits that are similar to those caused by receptor. motivation to act before they compromise the ability to lesions of the lateral hypothalamus can be induced REINFORCEMENT act. Such drugs do not immediately compromise the by selective damage to t