Clark L, Roiser J P, Cools R, Rubinsztein D C, Sahakian B J, Robbins T W
Department of Experimental Psychology, University of Cambridge, Downing Street, and Department of Medical Genetics, Addenbrooke's Hospital, Cambridge, UK.
Psychopharmacology (Berl). 2005 Nov;182(4):570-8. doi: 10.1007/s00213-005-0104-6. Epub 2005 Oct 19.
Reduced serotonin neurotransmission is implicated in disorders of impulse control, but the involvement of serotonin in inhibitory processes in healthy human subjects remains unclear.
To investigate the effects of an acute manipulation of serotonin and genotype at a functional polymorphism in a gene coding for the serotonin transporter (5-HTT) on an established measure of response inhibition.
Serotonin function was reduced by the acute tryptophan depletion (ATD) procedure in a double-blind, crossover design in 42 healthy subjects. The Stop Signal Task (SST) was administered 5-7 h after drink administration. The influences of 5-HTT polymorphism, gender and trait impulsivity were investigated.
ATD was associated with significant depletion of plasma tryptophan levels but did not increase the stop signal reaction time in comparison to the balanced (placebo) amino acid mixture. Subjects possessing the short allele of the 5-HTT polymorphism were not more impulsive on the SST than subjects homozygous for the long allele under placebo conditions and were not disproportionately sensitive to the effects of ATD. There was no effect of gender or trait impulsivity on ATD-induced change.
We find no support for the involvement of brain serotonin neurotransmission in this form of inhibitory control in healthy human subjects.
血清素神经传递减少与冲动控制障碍有关，但血清素在健康人类受试者抑制过程中的作用仍不清楚。
研究血清素的急性调控以及血清素转运体（5-HTT）编码基因功能多态性的基因型对既定反应抑制测量指标的影响。
在42名健康受试者中采用双盲交叉设计，通过急性色氨酸耗竭（ATD）程序降低血清素功能。饮用饮料5 - 7小时后进行停止信号任务（SST）。研究了5-HTT多态性、性别和特质冲动性的影响。
与平衡（安慰剂）氨基酸混合物相比，ATD与血浆色氨酸水平的显著降低有关，但并未增加停止信号反应时间。在安慰剂条件下，具有5-HTT多态性短等位基因的受试者在SST上并不比长等位基因纯合子受试者更冲动，且对ATD的影响也没有过度敏感。性别或特质冲动性对ATD诱导的变化没有影响。
我们没有发现证据支持脑血清素神经传递参与健康人类受试者这种形式的抑制控制。
