Horvitz Jon C, Choi Won Yung, Morvan Cecile, Eyny Yaniv, Balsam Peter D
Department of Psychology, Boston College, Chestnut Hill, MA 02467, USA.
Ann N Y Acad Sci. 2007 May;1104:270-88. doi: 10.1196/annals.1390.017. Epub 2007 Mar 14.
While extracellular dopamine (DA) concentrations are increased by a wide category of salient stimuli, there is evidence to suggest that DA responses to primary and conditioned rewards may be distinct from those elicited by other types of salient events. A reward-specific mode of neuronal responding would be necessary if DA acts to strengthen behavioral response tendencies under particular environmental conditions or to set current environmental inputs as goals that direct approach responses. As described in this review, DA critically mediates both the acquisition and expression of learned behaviors during early stages of training, however, during later stages, at least some forms of learned behavior become independent of (or less dependent upon) DA transmission for their expression.
虽然多种显著刺激会增加细胞外多巴胺（DA）浓度，但有证据表明，DA对初级奖励和条件性奖励的反应可能不同于其他类型显著事件所引发的反应。如果DA的作用是在特定环境条件下增强行为反应倾向，或者将当前环境输入设定为指导趋近反应的目标，那么神经元反应的奖励特异性模式将是必要的。如本综述所述，DA在训练早期阶段对学习行为的获得和表达起着关键的介导作用，然而，在后期阶段，至少某些形式的学习行为在表达上变得独立于（或较少依赖于）DA传递。
