Fusar-Poli Paolo, Allen Paul, Lee Francis, Surguladze Simon, Tunstall Nigel, Fu Cynthia H Y, Brammer Michael J, Cleare Anthony J, McGuire Philip K
Department of Applied and Psychobehavioural Health Sciences, University of Pavia, via Bassi 21, 27100, Pavia, Italy.
Psychopharmacology (Berl). 2007 Jul;193(1):31-44. doi: 10.1007/s00213-007-0757-4. Epub 2007 Mar 21.
Central serotonin (5HT) plays a major role in emotional processing. We used functional neuroimaging (fMRI) to investigate the effects of experimental manipulation of central 5HT levels on the regional neural response to happy and sad facial expressions.
Ten healthy participants (eight men and two women) were scanned during an implicit emotional processing task after receiving a tryptophan-free (acute tryptophan depletion, ATD) or a balanced amino acid drink in a double-blind design.
ATD lowered total plasma tryptophan concentration by 80%. There was no significant effect on subjective mood ratings, on response accuracy and on reaction times. Compared to sham depletion, ATD attenuated activation in the right medial/inferior frontal gyrus, the posterior cingulate cortex, the occipital and parietal cortex bilaterally, the right hippocampus, claustrum and insula. Conversely, ATD was associated with relatively increased activation in the left inferior frontal gyrus. ATD had differential effects on activation during the processing of happy and sad faces in the right putamen and in the left superior temporal gyrus.
In both cortical and sub-cortical regions, the neural response associated with processing emotional faces is significantly modulated by 5HT manipulation resulting from ATD. Moreover, in certain areas, this effect of 5HT depends on the emotional valence of the stimulus.
中枢5-羟色胺（5HT）在情绪加工中起主要作用。我们使用功能神经成像（fMRI）来研究中枢5HT水平的实验性调控对区域神经对开心和悲伤面部表情反应的影响。
10名健康参与者（8名男性和2名女性）在双盲设计中接受无色氨酸（急性色氨酸耗竭，ATD）或平衡氨基酸饮料后，在一项内隐情绪加工任务中接受扫描。
ATD使血浆总色氨酸浓度降低了80%。对主观情绪评分、反应准确性和反应时间没有显著影响。与假耗竭相比，ATD减弱了右侧内侧/额下回、后扣带回皮质、双侧枕叶和顶叶皮质、右侧海马体、屏状核和脑岛的激活。相反，ATD与左侧额下回激活相对增加有关。ATD对右侧壳核和左侧颞上回在加工开心和悲伤面孔时的激活有不同影响。
在皮质和皮质下区域，与加工情绪面孔相关的神经反应受到ATD导致的5HT调控的显著调节。此外，在某些区域，5HT的这种作用取决于刺激的情绪效价。
