Department of Psychiatry, McGill University, Montréal, QC, H3A 1A1, Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, QC, H3A 2B4, Canada.
Synapse. 2013 Dec;67(12):821-30. doi: 10.1002/syn.21700. Epub 2013 Sep 12.
In laboratory animals, environmental stressors markedly activate the mesocortical dopamine system. The present study tested whether this occurs in humans.
The effects of a laboratory psychological stressor (Montreal Imaging Stress Task, MIST) on mesocortical dopamine release in healthy young adults (11 males, mean age ± SD, 20.6 ± 2.4 years) was measured using positron emission tomography and [(18)F]fallypride. Each subject was scanned in two separate days in counterbalanced order: one with the MIST and one with the control task. Binding potential (BP ND ) maps of the whole brain were calculated for each scan, using a simplified reference tissue compartmental model. Then BP ND was compared between subjects. Heart rate, galvanic skin response, and salivary cortisol level were measured during the scans.
The psychological stressor significantly decreased [(18)F]fallypride binding values in the dorsal part of the medial prefrontal cortex (dmPFC), corresponding to the rostal part of the cingulate motor zone. The greater the stress-induced decrease in [(18)F]fallypride binding in the dmPFC, the greater the stress-induced increases in heart rate.
The present study provides evidence of stress-induced dopamine release in the mPFC in humans, in vivo.
在实验动物中，环境应激因素会显著激活中皮质多巴胺系统。本研究旨在测试这种情况是否发生在人类中。
采用正电子发射断层扫描和 [(18)F]fallypride 检测健康年轻成年人（11 名男性，平均年龄 ± 标准差，20.6 ± 2.4 岁）在实验室心理应激（蒙特利尔成像应激任务，MIST）下中皮质多巴胺的释放。每位受试者在两个不同的日子以平衡的方式进行两次扫描：一次进行 MIST，一次进行对照任务。使用简化的参考组织室模型计算每次扫描的整个大脑的结合潜力 (BP ND) 图。然后比较受试者之间的 BP ND。在扫描过程中测量心率、皮肤电反应和唾液皮质醇水平。
心理应激显著降低了背外侧前额叶皮质 (dmPFC) 背侧部分的 [(18)F]fallypride 结合值，与扣带运动区的前部分相对应。dmPFC 中 [(18)F]fallypride 结合的应激诱导减少越多，心率的应激诱导增加越大。
本研究提供了人类在体中皮质多巴胺释放的应激诱导证据。
