Dissociable roles for the nucleus accumbens core and shell in regulating set shifting
Dissociable roles for the nucleus accumbens core and shell in regulating set shifting
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DOI：
10.1523/jneurosci.4431-05.2006
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发表时间：
2006-03-01
影响因子：
5.3
通讯作者：
Magyar, O
中科院分区：
文献类型：
--
作者：
Floresco, SB;Ghods-Sharifi, S;Magyar, O
以灵活的方式行事的能力是一种执行功能，部分由前额叶皮层的不同区域介导。本研究采用基于迷宫的策略转换任务，探讨了前额叶皮层的两个主要传出神经核（NAc）核芯和壳在行为灵活性中的作用。在最初的辨别训练中，大鼠学会了使用自我中心反应或视觉线索辨别策略来获得食物奖励。在集合转换过程中，动物必须从先前获得的反应或基于视觉线索的策略转换，并学习交替的辨别。失活的NAC核心，诱导注入GABA激动剂巴氯芬和蝇蕈醇，并没有损害初始收购的反应或视觉线索的歧视，但严重破坏了从一个战略转移到另一个。错误类型的分析表明，在集转移的损害是不是由于增加坚持，但中断的收购和维护一个新的战略。与此相反，NAc壳的失活并没有损害收购的反应或视觉线索的歧视，或从一个战略转移到另一个。然而，灭活的NAc壳在初始的歧视培训提高性能，在设置的转变相对于对照组动物。这些数据表明，NAc的核心和外壳的行为灵活性，在设置转换的贡献。NAc核心有助于获得和维持新的行为策略和消除不适当的反应选项，而外壳可能介导学习无关的刺激。
The ability to behave in a flexible manner is an executive function mediated in part by different regions of the prefrontal cortex. The present study investigated the role of two major efferents of the prefrontal cortex, the nucleus accumbens (NAc) core and shell, in behavioral flexibility using a maze-based strategy set-shifting task. During initial discrimination training, rats learned to use either an egocentric response or a visual-cue discrimination strategy to obtain food reward. During the set shift, animals had to shift from the previously acquired response or visual-cue-based strategy and learn the alternate discrimination. Inactivation of the NAc core, induced by infusion of the GABA agonists baclofen and muscimol, did not impair initial acquisition of either a response or visual-cue discrimination but severely disrupted shifting from one strategy to another. Analysis of the type of errors revealed that impairments in set shifting were not attributable to increased perseveration but to a disruption of the acquisition and maintenance of a new strategy. In contrast, inactivation of the NAc shell did not impair acquisition of either a response or a visual-cue discrimination, or shifting from one strategy to another. However, inactivation of the NAc shell before initial discrimination training improved performance during the set shift relative to control animals. These data indicate that the NAc core and shell make dissociable contributions to behavioral flexibility during set shifting. The NAc core facilitates the acquisition and maintenance of novel behavioral strategies and elimination of inappropriate response options, whereas the shell may mediate learning about irrelevant stimuli.