Department of Psychology, University of British Columbia, Vancouver, British Columbia, Canada.
J Neurosci. 2012 Feb 22;32(8):2886-99. doi: 10.1523/JNEUROSCI.5625-11.2012.
Choosing between smaller, assured rewards or larger, uncertain ones requires reconciliation of competing biases toward more certain or riskier options. We used disconnection and neuroanatomical techniques to reveal that separate, yet interconnected, neural pathways linking the medial prefrontal cortex (PFC), the basolateral amygdala (BLA), and nucleus accumbens (NAc) contribute to these different decision biases in rats. Disrupting communication between the BLA and NAc revealed that this subcortical circuit biases choice toward larger, uncertain rewards on a probabilistic discounting task. In contrast, disconnections between the BLA and PFC increased choice of the Large/Risky option. PFC-NAc disconnections did not affect choice but did increase choice latencies and trial omissions. Neuroanatomical studies confirmed that projection pathways carrying axons from BLA-to-PFC transverse a distinctly different route relative to PFC-to-BLA pathways (via the ventrolateral amydalofugal pathway and ventromedial internal capsule, respectively). We exploited these dissociable axonal pathways to selectively disrupt bottom-up and top-down communication between the BLA and PFC. Subsequent disconnection studies revealed that disruption of top-down (but not bottom-up) information transfer between the medial PFC and BLA increased choice of the larger, riskier option, suggesting that this circuit facilitates tracking of actions and outcomes to temper urges for riskier rewards as they become less profitable. These findings provide novel insight into the dynamic competition between these cortical/subcortical circuits that shape our decision biases and underlie conflicting urges when evaluating options that vary in terms of potential risks and rewards.
在较小、确定的奖励和较大、不确定的奖励之间进行选择,需要协调对更确定或风险更大选项的竞争偏见。我们使用断开和神经解剖技术来揭示连接内侧前额叶皮层(PFC)、基底外侧杏仁核(BLA)和伏隔核(NAc)的独立但相互连接的神经通路,这些通路有助于大鼠做出不同的决策偏见。破坏 BLA 和 NAc 之间的通信表明,这个皮质下回路偏向于在概率折扣任务中选择更大、不确定的奖励。相比之下,BLA 和 PFC 之间的连接中断增加了对大/风险选项的选择。PFC-NAc 连接中断不会影响选择,但会增加选择潜伏期和试验遗漏。神经解剖学研究证实,携带来自 BLA 到 PFC 的轴突的投射通路与 PFC 到 BLA 的通路(分别通过腹外侧杏仁核传出通路和腹内侧内囊)相比,具有明显不同的途径。我们利用这些可分离的轴突通路,选择性地破坏 BLA 和 PFC 之间的自上而下和自下而上的通信。随后的断开连接研究表明,破坏内侧 PFC 和 BLA 之间的自上而下(而不是自下而上)信息传递增加了对更大、风险更大的选择,这表明该回路有助于跟踪行动和结果,以抑制对风险更大奖励的冲动,因为它们的利润变得越来越低。这些发现为这些皮层/皮质下回路之间的动态竞争提供了新的见解,这些竞争塑造了我们的决策偏见,并为评估潜在风险和奖励不同的选项时产生的冲突冲动提供了基础。