Dept. of Psychology, University of Connecticut, Storrs, CT 06269-1020, USA.
J Exp Anal Behav. 2012 Jan;97(1):125-46. doi: 10.1901/jeab.2012.97-125.
For many years, it has been suggested that drugs that interfere with dopamine (DA) transmission alter the "rewarding" impact of primary reinforcers such as food. Research and theory related to the functions of mesolimbic DA are undergoing a substantial conceptual restructuring, with the traditional emphasis on hedonia and primary reward yielding to other concepts and lines of inquiry. The present review is focused upon the involvement of nucleus accumbens DA in effort-related choice behavior. Viewed from the framework of behavioral economics, the effects of accumbens DA depletions and antagonism on food-reinforced behavior are highly dependent upon the work requirements of the instrumental task, and DA-depleted rats show a heightened sensitivity to response costs, especially ratio requirements. Moreover, interference with accumbens DA transmission exerts a powerful influence over effort-related choice behavior. Rats with accumbens DA depletions or antagonism reallocate their instrumental behavior away from food-reinforced tasks that have high response requirements, and show increased selection of low reinforcement/low cost options. Nucleus accumbens DA and adenosine interact in the regulation of effort-related functions, and other brain structures (anterior cingulate cortex, amygdala, ventral pallidum) also are involved. Studies of the brain systems regulating effort-based processes may have implications for understanding drug abuse, as well as symptoms such as psychomotor slowing, fatigue or anergia in depression and other neurological disorders.
多年来，人们一直认为干扰多巴胺（DA）传递的药物会改变食物等主要强化物的“奖赏”作用。与中脑边缘 DA 功能相关的研究和理论正在经历实质性的概念重构，传统上对享乐和初级奖赏的强调让位于其他概念和研究方向。本综述重点关注伏隔核 DA 在与努力相关的选择行为中的作用。从行为经济学的角度来看，伏隔核 DA 耗竭和拮抗作用对食物强化行为的影响高度依赖于工具任务的工作要求，DA 耗竭大鼠对反应成本更为敏感，尤其是比率要求。此外，干扰伏隔核 DA 传递对与努力相关的选择行为有强大的影响。伏隔核 DA 耗竭或拮抗的大鼠会将其工具行为从需要高反应要求的食物强化任务中重新分配，并增加对低强化/低成本选项的选择。伏隔核 DA 和腺苷在与努力相关的功能调节中相互作用，其他脑结构（扣带前皮质、杏仁核、腹侧苍白球）也参与其中。研究调节基于努力的过程的大脑系统可能有助于理解药物滥用，以及抑郁症和其他神经障碍中的精神运动迟缓、疲劳或无力等症状。
