Converging evidence from studies with animals and humans have implicated separate regions of the medial prefrontal cortex (mPFC) corresponding to the anterior cingulate cortex (ACC), in mediating different aspects of reward-related decisions involving uncertainty or risk. However, the dissociable contributions of subregions of the ACC remain unclear, as discrepancies exist between human neuroimaging findings and preclinical rodent studies. To clarify how ventral vs. dorsal regions of the mPFC contribute to risk/reward decision making, the present study assessed the effects of inactivation of different subregions on performance of a "Blackjack task" that measured cue-guided decision making and shares similarities with paradigms used with humans. Male, Long-Evans rats were well-trained to choose between a Small/Certain reward vs a Large/Risky reward delivered with variable probabilities (i.e., good vs. poor-odds, 50% vs. 12.5%). The odds of obtaining the larger reward was signaled by auditory cues at the start of each trial. Inactivation of the ventral, infralimbic region of the mPFC increased risky choice selectively when the odds of winning were poor. By contrast, inactivation of the prelimbic and anterior cingulate regions of the dorsal mPFC led to suboptimal reductions in risky choice on good-odds trials. The effects of prelimbic vs anterior cingulate inactivations were associated with context-dependent alterations in reward vs negative feedback, respectively. These results further clarify the distinct yet complementary manners in which separate ACC regions promote optimal risk/reward decision making and complement neuroimaging findings that activity in human ventral vs dorsal ACC promotes risk aversion or risky choices.

中文翻译：

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腹侧和背侧内侧前额叶皮层在提示引导的风险/回报决策中的可分离作用。

来自动物和人类的研究的越来越多的证据暗示，在涉及不确定性或风险的奖励相关决策的不同方面，内侧前额叶皮层（mPFC）的各个区域对应于前扣带回皮层（ACC）。然而，由于人类神经影像学发现与临床前啮齿类动物研究之间存在差异，ACC子区域的可分离贡献仍不清楚。为了阐明mPFC的腹侧和背侧区域如何对风险/奖励决策做出贡献，本研究评估了不同子区域的失活对“二十一点任务”绩效的影响，该“二十一点任务”测量了线索指导的决策，并与范式具有相似性与人类一起使用。男性，对Long-Evans大鼠进行了良好的训练，可以在概率可变的小/某些奖励与大/危险奖励之间进行选择（即，好几率与几分几率，分别为50％和12.5％）。在每次试验开始时，听觉提示表明获得更大奖励的几率。当获胜的可能性很低时，mPFC的腹侧，下缘区域的失活会选择性地增加风险选择。相比之下，在好几率试验中，背侧mPFC的前缘和前扣带回区域的失活导致风险选择的次优降低。前缘与前扣带回失活的影响分别与奖励与否定反馈的情境相关改变有关。