Yang Minzhe, Fu Qiangpei, Ma Chaolin, Li Baoming
School of Life Science and Institute of Life Science, Nanchang University, Nanchang, China.
School of Basic Medical Sciences and Institute of Brain Science, Hangzhou Normal University, Hangzhou, China.
Front Behav Neurosci. 2022 Jul 11;16:934834. doi: 10.3389/fnbeh.2022.934834. eCollection 2022.
Risky decision-making is the decision made by individuals when they know the probability of each outcome. In order to survive in unpredictable environments, it is necessary for individuals to assess the probability of events occurring to an make appropriate decisions. There are few studies on the neural basis of risky decision-making behavior guided by external cues, which is related to the relative paucity of animal behavioral paradigms. Previous studies have shown that the prefrontal cortex (PFC) plays a key role in risk-based decision-making. The PFC receives projections from the dopamine (DA) system from the ventral tegmental area of the midbrain. The mesocorticolimbic DA system regulates the judgments of reward and value in decision-making. However, the specific receptor mechanism for prefrontal DA regulation of cue-guided risky decision-making behavior remains unclear. Here we established a cue-guided risky decision-making behavioral paradigm (RDM task) to detect the behavior of rats making decisions between a small certain reward and a large uncertain reward in a self-paced manner. The D1 receptor antagonist SCH-23390 (5 mM) or agonist SKF-82958 (5 mM), and the D2 receptor antagonist thioridazine hydrochloride (5 mM) or agonist MLS-1547 (5 mM) was injected into the mPFC, respectively, to investigate how the behavior in the RDM task was changed. The results showed that: (1) rats were able to master the operation of the cue-guided RDM task in a self-paced way; (2) a majority of rats were inclined to choose risk rather than a safe option when the reward expectations were equal; and (3) risk selection was reduced upon inhibition of D1 receptors or stimulation of D2 receptors, but increased upon stimulation of D1 receptors or inhibition of D2 receptors, suggesting that the RDM performance is regulated by D1 and D2 receptors in the mPFC. The present results suggest that DA receptors in the mPFC of rats are involved in regulating cue-guided RDM behavior, with differential involvement of D1 and D2 receptors in the regulation.
风险决策是个体在知晓每种结果发生概率时所做出的决策。为了在不可预测的环境中生存，个体有必要评估事件发生的概率并做出恰当决策。目前关于外部线索引导的风险决策行为神经基础的研究较少，这与动物行为范式相对匮乏有关。以往研究表明，前额叶皮质（PFC）在基于风险的决策中起关键作用。PFC接收来自中脑腹侧被盖区多巴胺（DA）系统的投射。中脑皮质边缘DA系统调节决策过程中的奖励和价值判断。然而，前额叶DA调节线索引导的风险决策行为的具体受体机制仍不清楚。在此，我们建立了一种线索引导的风险决策行为范式（RDM任务），以检测大鼠在自定节奏的情况下，在小的确定性奖励和大的不确定性奖励之间做出决策的行为。分别向内侧前额叶皮质注射D1受体拮抗剂SCH-23390（5 mM）或激动剂SKF-82958（5 mM），以及D2受体拮抗剂盐酸硫利达嗪（5 mM）或激动剂MLS-1547（5 mM），以研究RDM任务中的行为如何变化。结果表明：（1）大鼠能够自定节奏地掌握线索引导的RDM任务操作；（2）当奖励期望相等时，大多数大鼠倾向于选择风险而非安全选项；（3）抑制D1受体或刺激D2受体时风险选择减少，但刺激D1受体或抑制D2受体时风险选择增加，这表明内侧前额叶皮质中的D1和D2受体调节RDM表现。目前的结果表明，大鼠内侧前额叶皮质中的DA受体参与调节线索引导的RDM行为，且D1和D2受体在调节过程中的参与存在差异。
