Lowering of serotonin by rapid tryptophan depletion increases impulsiveness in normal individuals
Lowering of serotonin by rapid tryptophan depletion increases impulsiveness in normal individuals
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DOI：
10.1007/s00213-002-1238-4
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发表时间：
2002-12-01
影响因子：
3.4
通讯作者：
Magnusson, A
中科院分区：
文献类型：
--
作者：
Walderhaug, E;Lunde, H;Magnusson, A
理论基础：5-羟色胺能活性降低与冲动行为有关；然而，干预研究一直很少。目的：研究5-羟色胺(5-羟色胺)水平的降低是否会增加冲动的行为测量。方法：在平衡、随机、双盲、安慰剂对照、交叉研究设计中，24名健康的年轻男性摄入了除色氨酸以外的多种必需氨基酸。当色氨酸的血浆浓度预计处于最低点时，进行连续性能测试的等同配对。分别于基础状态和摄入混合氨基酸后5h测定血浆中23种氨基酸的浓度。结果：干预后血浆游离色氨酸、总色氨酸、色氨酸/大分子中性氨基酸比值显著下降。这反过来又被证明可以降低中枢神经系统中5-羟色胺的水平。当受试者解决口头任务时，色氨酸耗竭导致在连续操作测试相同的配对上，在统计上显着更具冲动性-或去抑制的反应风格。暴露在空间刺激下的精疲力竭的受试者正确反应较少，辨别刺激的能力降低。结论：这些结果表明，色氨酸的快速降低增加了正常人的冲动，降低了辨别能力。在这项研究中，5-羟色胺缺乏对辨别能力的影响与以前在抑郁症患者中报道的相似。
Rationale: Reduced serotonergic activity has been associated with impulsive behavior; however, intervention studies have been scarce. Objectives: To examine whether induced lowering of serotonin (5-HT) levels would increase behavioral measures of impulsivity. Methods: Twenty-four healthy young males ingested a mixture of the essential amino acids except for tryptophan in a balanced, randomized, double-blind, placebo-controlled, cross-over study design. The continuous-performance test-identical pairs was administered when the plasma concentration of tryptophan was expected to be at the lowest point. The plasma concentrations of 23 amino acids were measured at baseline and 5 h after the ingestion of the amino acid mixture. Results: The intervention led to a dramatic fall in free and total plasma tryptophan, and the tryptophan/large neutral amino acids ratio. This in turn has been shown to lower the level of 5-HT in the central nervous system. The tryptophan depletion resulted in a statistically significant more impulsive- or disinhibited response style on the continuous -performance test-identical pairs when the subjects were solving verbal tasks. Depleted subjects exposed to spatial stimuli had fewer correct responses and a decreased ability to discriminate between stimuli. Conclusions: These results indicate that a rapid lowering of tryptophan increases impulsiveness and decreases discriminating ability in normal individuals. The effect of 5-HT depletion on discriminating ability in this study was similar to that previously reported in depressed patients.