Risk perception is an important factor that may mediate risk-based decision-making processes regulated by noradrenergic (NA) and serotonergic (5-HT) systems. Most risk-based decision-making models involve complex factors, such as risk perception or reward value, such that the final decision is the result of the interactions among these factors. However, the contribution of risk perception per se in risk decisions has remained unclear. Therefore, in the present study, we made some modifications to the classical probabilistic discounting task (PDT) to focus on the impact of risk perception and noradrenergic/serotonergic systems on decision-making behavior. Meanwhile, we conducted an elevated plus-maze (EPM) test to detect the correlation between anxiety and choice behavior. In the current study, rats had to choose between a “certain” lever that delivered a certain number of pellets and a “risky” lever that delivered eight pellets in a probabilistic manner (descending: 50%, 25%, 12.5% or ascending 12.5%, 25%, 50% of the time). The long-term rewarding values of the two levers were always identical in each block within each session. According to their baseline performances in choosing the risky lever, rats were divided into the risk-prefer group and risk-averse group. The results showed that there was a significant correlation between open arm time in EPM and risky choice for both descending order and ascending order, indicating that highly anxious rats more often preferred the safe option under risk. Pharmacological stimulation of α2-adrenergic receptors via dexmedetomidine (0.01 mg/kg) decreased the preference of probabilistic rewards in the risk-prefer group, while blocking α2 receptors by atipamezole (0.3 mg/kg) also reduced risky choices. The NA reuptake inhibitor, atomoxetine, increased the preference for risky choices in the risk-prefer group, the effect of which was attained via multiple superimposed doses. Administration of the 5-HT_2A receptor agonist, DOI (0.1 mg/kg), increased risk-taking behavior in the risk-prefer group. Taken together, these results suggest that NA may be more inclined to process negative information such as loss or uncertainty in the regulation of risk-related decision making, whereas 5-HT may function primarily to increase risk-taking behavior. Our findings may help to further elucidate how noradrenergic and serotonergic systems differentially affect individuals with different risk preferences in terms of regulating risk perception in risk-related decision making.

风险感知是一个重要的因素，可以调节由去甲肾上腺素能 (NA) 和血清素 (5-HT) 系统调节的基于风险的决策过程。大多数基于风险的决策模型涉及复杂的因素，例如风险感知或奖励价值，因此最终决策是这些因素之间相互作用的结果。然而，风险感知本身在风险决策中的贡献仍不清楚。因此，在本研究中，我们对经典概率贴现任务 (PDT) 进行了一些修改，以关注风险感知和去甲肾上腺素能/血清素能系统对决策行为的影响。同时，我们进行了高架十字迷宫 (EPM) 测试，以检测焦虑与选择行为之间的相关性。在目前的研究中，大鼠必须在一个“确定”的杠杆和一个以概率方式输送八个颗粒的“风险”杠杆之间进行选择（下降：50%、25%、12.5%或上升 12.5%、25%、 50% 的时间）。在每个会话的每个块中，两个杠杆的长期回报值始终相同。根据选择风险杠杆的基线表现，将大鼠分为风险偏好组和风险厌恶组。结果表明，EPM 的开放臂时间与降序和升序的风险选择之间存在显着相关性，表明高度焦虑的大鼠更倾向于在风险下选择安全选项。通过右美托咪定 (0. 01 mg/kg) 降低了风险偏好组中概率奖励的偏好，而通过阿替美唑 (0.3 mg/kg) 阻断 α2 受体也减少了风险选择。NA 再摄取抑制剂托莫西汀增加了风险偏好组对风险选择的偏好，其效果是通过多个叠加剂量实现的。5-HT 的管理_2A受体激动剂 DOI (0.1 mg/kg) 增加了风险偏好组的冒险行为。综上所述，这些结果表明 NA 可能更倾向于处理负面信息，例如风险相关决策监管中的损失或不确定性，而 5-HT 可能主要用于增加冒险行为。我们的发现可能有助于进一步阐明去甲肾上腺素能和血清素能系统如何在调节风险相关决策中的风险感知方面对具有不同风险偏好的个体产生不同的影响。