Serotonin shapes risky decision making in monkeys
Serotonin shapes risky decision making in monkeys
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DOI：
10.1093/scan/nsp020
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发表时间：
2009-12-01
影响因子：
4.2
通讯作者：
Platt, Michael L.
中科院分区：
文献类型：
--
作者：
Long, Arwen B.;Kuhn, Cynthia M.;Platt, Michael L.
有些人喜欢冒险，而另一些人则不惜一切代价避免赌博。然而，对风险或某些结果偏好的个体差异的神经机制仍然知之甚少。尽管与强迫性赌博、成瘾和其他精神疾病相关的行为病理学暗示病理决策中缺乏5-羟色胺信号传导，但很少有实验证据表明5-羟色胺与风险决策之间存在联系，部分原因是缺乏良好的动物模型。我们使用饮食快速色氨酸耗竭（RTD）来急性降低三只猕猴的大脑5-羟色胺，这些猕猴执行一项简单的赌博任务以获得液体奖励。为了确认RTD实验的有效性，我们使用高效液相色谱法（HPLC）和电化学检测器测量了血浆总色氨酸。减少大脑中5-羟色胺的合成会降低赌博任务中对安全选项的偏好。此外，降低大脑5-羟色胺功能显著降低了猴子将偏好转向风险选项所需的溢价，这表明5-羟色胺信号的减少增强了风险选项的相对主观价值。这些结果暗示5-羟色胺在风险敏感的决策，并进一步建议药理学治疗的疾病，如问题赌博和成瘾的病理风险偏好。
Some people love taking risks, while others avoid gambles at all costs. The neural mechanisms underlying individual variation in preference for risky or certain outcomes, however, remain poorly understood. Although behavioral pathologies associated with compulsive gambling, addiction and other psychiatric disorders implicate deficient serotonin signaling in pathological decision making, there is little experimental evidence demonstrating a link between serotonin and risky decision making, in part due to the lack of a good animal model. We used dietary rapid tryptophan depletion (RTD) to acutely lower brain serotonin in three macaques performing a simple gambling task for fluid rewards. To confirm the efficacy of RTD experiments, we measured total plasma tryptophan using high-performance liquid chromatography (HPLC) with electrochemical detection. Reducing brain serotonin synthesis decreased preference for the safe option in a gambling task. Moreover, lowering brain serotonin function significantly decreased the premium required for monkeys to switch their preference to the risky option, suggesting that diminished serotonin signaling enhances the relative subjective value of the risky option. These results implicate serotonin in risk-sensitive decision making and, further, suggest pharmacological therapies for treating pathological risk preferences in disorders such as problem gambling and addiction.