Cole Sindy, Stone Andrew D, Petrovich Gorica D
Department of Psychology, Boston College.
Behav Neurosci. 2017 Dec;131(6):447-453. doi: 10.1037/bne0000216.
The dorsomedial striatum (DMS) is an important sensorimotor region mediating the acquisition of goal-directed instrumental reward learning and behavioral flexibility. However, whether the DMS also regulates Pavlovian cue-food learning is less clear. The current study used excitotoxic lesions to determine whether the DMS is critical in Pavlovian appetitive learning and behavior, using discriminative conditioning and reversal paradigms. The results showed that DMS lesions transiently retarded cue-food learning and subsequent reversal of this learning. Rats with DMS lesions selectively attenuated responding to a food cue but not a control cue, early in training, suggesting the DMS is involved when initial associations are formed. Similarly, initial reversal learning was attenuated in rats with DMS lesions, which suggests impaired flexibility to adjust behavior when the cue meaning is reversed. We also examined the effect of DMS lesions on food intake during tests with access to a highly palatable food along with standard chow diet. Rats with DMS lesions showed an altered pattern of intake, with an initial reduction in high-fat diet followed by an increase in chow consumption. These results demonstrate that the DMS has a role in mediating cue-food learning and its subsequent reversal, as well as changes in food intake when a choice is provided. Together, these results demonstrate the DMS is involved in reward associative learning and reward consumption, when behavioral flexibility is needed to adjust responding or consumption to match the current value. (PsycINFO Database Record
背内侧纹状体（DMS）是一个重要的感觉运动区域，介导目标导向的工具性奖励学习和行为灵活性的获得。然而，DMS是否也调节巴甫洛夫线索-食物学习尚不清楚。当前的研究使用兴奋性毒性损伤来确定DMS在巴甫洛夫式食欲学习和行为中是否至关重要，采用辨别性条件反射和反转范式。结果表明，DMS损伤会暂时延缓线索-食物学习以及随后这种学习的反转。在训练早期，DMS损伤的大鼠对食物线索的反应选择性减弱，但对对照线索的反应没有减弱，这表明在形成初始关联时DMS参与其中。同样，DMS损伤的大鼠的初始反转学习也减弱了，这表明当线索意义反转时，调整行为的灵活性受损。我们还研究了DMS损伤对在可获取高度可口食物以及标准食物的测试期间食物摄入量的影响。DMS损伤的大鼠表现出改变的摄入模式，即高脂肪饮食最初减少，随后普通食物的消耗量增加。这些结果表明，DMS在介导线索-食物学习及其随后的反转以及提供选择时食物摄入量的变化中发挥作用。总之，这些结果表明，当需要行为灵活性来调整反应或消耗以匹配当前价值时，DMS参与奖励联想学习和奖励消耗。（PsycINFO数据库记录）
