Reconciling the role of serotonin in behavioral inhibition and aversion: acute tryptophan depletion abolishes punishment-induced inhibition in humans.
Reconciling the role of serotonin in behavioral inhibition and aversion: acute tryptophan depletion abolishes punishment-induced inhibition in humans.
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DOI：
10.1523/jneurosci.2513-09.2009
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发表时间：
2009-09-23
期刊：
影响因子：
--
通讯作者：
Robbins TW
中科院分区：
文献类型：
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作者：
Crockett MJ;Clark L;Robbins TW
神经调节剂5-羟色胺与大量的情感和执行功能有关，但它对动机的确切贡献仍不清楚。一个有影响力的假说认为血清素与厌恶性加工有关;另一个假说则认为血清素在行为抑制中起着更普遍的作用。由于行为抑制是对令人厌恶的结果的一种预先有效的反应，因此调和这两种解释一直是一个挑战。在这里，我们表明，5-羟色胺是至关重要的惩罚诱导的抑制，但不是整体运动反应抑制或报告令人厌恶的结果。我们使用急性色氨酸耗竭暂时降低健康志愿者的大脑5-羟色胺，因为他们完成了一项新的任务，旨在获得运动反应抑制，惩罚诱导的抑制和厌恶结果的敏感性的单独措施。在安慰剂治疗后，与奖励条件相比，参与者在惩罚条件下的反应较慢。色氨酸耗尽废除了这种惩罚诱导的抑制，而不影响整体运动反应抑制或调整响应偏差的能力，符合惩罚突发事件。减少惩罚诱导的抑制的幅度取决于色氨酸耗竭降低血浆色氨酸水平的程度。这些发现扩展并澄清了先前关于5-羟色胺在厌恶性加工和行为抑制中的作用的研究，并与目前关于5-羟色胺参与预测厌恶性结果的理论相吻合。
The neuromodulator serotonin has been implicated in a large number of affective and executive functions, but its precise contribution to motivation remains unclear. One influential hypothesis has implicated serotonin in aversive processing; another has proposed a more general role for serotonin in behavioral inhibition. Since behavioral inhibition is a pre-potent reaction to aversive outcomes, it has been a challenge to reconcile these two accounts. Here, we show that serotonin is critical for punishment-induced inhibition, but not overall motor response inhibition or reporting aversive outcomes. We used acute tryptophan depletion to temporarily lower brain serotonin in healthy human volunteers as they completed a novel task designed to obtain separate measures of motor response inhibition, punishment-induced inhibition, and sensitivity to aversive outcomes. Following a placebo treatment, participants were slower to respond under punishment conditions, compared to reward conditions. Tryptophan depletion abolished this punishment-induced inhibition, without affecting overall motor response inhibition or the ability to adjust response bias in line with punishment contingencies. The magnitude of reduction in punishment-induced inhibition depended on the degree to which tryptophan depletion reduced plasma tryptophan levels. These findings extend and clarify previous research on the role of serotonin in aversive processing and behavioral inhibition, and fit with current theorizing on serotonin's involvement in predicting aversive outcomes.