Effects of selective serotonin reuptake inhibition on neural activity related to risky decisions and monetary rewards in healthy males
Effects of selective serotonin reuptake inhibition on neural activity related to risky decisions and monetary rewards in healthy males
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DOI：
10.1016/j.neuroimage.2014.05.040
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发表时间：
2014-10-01
期刊：
影响因子：
5.7
通讯作者：
Siebner, Hartwig R.
中科院分区：
文献类型：
--
作者：
Macoveanu, Julian;Fisher, Patrick M.;Siebner, Hartwig R.
氟西汀等选择性血清素再摄取抑制剂 (SSRI) 是常用的抗抑郁药物，针对功能失调的血清素 (5-HT) 系统，但人们对长期血清素再摄取抑制对健康个体的功能影响知之甚少。在这里，我们使用功能性 MRI (fMRI) 来研究为期三周的氟西汀干预如何影响与风险承担和奖励处理相关的神经活动。采用双盲平行组设计，29 名健康年轻男性被随机分配接受为期 3 周的每日剂量 40 mg 氟西汀或安慰剂。参与者在执行纸牌赌博任务时，在三周干预之前和之后接受了与任务相关的功能磁共振成像。该任务要求参与者在两副牌之间进行选择。选择与不同的风险水平和潜在的回报大小相关。相对于安慰剂，SSRI干预并没有改变个人的风险选择偏好，但改变了决策和奖励处理过程中的神经活动：在选择阶段，SSRI减少了外侧眶额皮质（基于价值决策的关键结构）对风险增加的神经反应。在结果阶段，中脑区域对奖励结果的反应表现出独立下降。这个中脑簇包括中缝核，血清素调节投射从中缝核发往皮质和皮质下区域。研究结果证实了正常运作的 5HT 系统参与风险决策和金钱奖励处理。数据表明，长期 SSRI 治疗可能会通过减少决策过程中风险的影响或结果评估过程中奖励的影响来减少情绪投入。 (C) 2014 爱思唯尔公司保留所有权利。
Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine are commonly prescribed antidepressant drugs targeting the dysfunctional serotonin (5-HT) system, yet little is known about the functional effects of prolonged serotonin reuptake inhibition in healthy individuals. Here we used functional MRI (fMRI) to investigate how a three-week fluoxetine intervention influences neural activity related to risk taking and reward processing.Employing a double-blinded parallel-group design, 29 healthy young males were randomly assigned to receive 3 weeks of a daily dose of 40 mg fluoxetine or placebo. Participants underwent task-related fMRI prior to and after the three-week intervention while performing a card gambling task. The task required participants to choose between two decks of cards. Choices were associated with different risk levels and potential reward magnitudes.Relative to placebo, the SSRI intervention did not alter individual risk-choice preferences, but modified neural activity during decision-making and reward processing: During the choice phase, SSRI reduced the neural response to increasing risk in lateral orbitofrontal cortex, a key structure for value-based decision-making. During the outcome phase, a midbrain region showed an independent decrease in the responsiveness to rewarding outcomes. This midbrain cluster included the raphe nuclei from which serotonergic modulatory projections originate to both cortical and subcortical regions.The findings corroborate the involvement of the normally functioning 5HT-system in decision-making under risk and processing of monetary rewards. The data suggest that prolonged SSRI treatment might reduce emotional engagement by reducing the impact of risk during decision-making or the impact of reward during outcome evaluation. (C) 2014 Elsevier Inc All rights reserved.