Wardle Margaret C, Fitzgerald Daniel A, Angstadt Michael, Rabinak Christine A, de Wit Harriet, Phan K Luan
Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S. Maryland Ave., MC 3077, Chicago, IL, 60637, USA,
Psychopharmacology (Berl). 2014 Nov;231(22):4403-15. doi: 10.1007/s00213-014-3592-4. Epub 2014 May 7.
Evidence from animal and human studies suggests that opiate drugs decrease emotional responses to negative stimuli and increase responses to positive stimuli. Such emotional effects may motivate misuse of oxycodone (OXY), a widely abused opiate. Yet, we know little about how OXY affects neural circuits underlying emotional processing in humans.
We examined effects of OXY on brain activity during presentation of positive and negative visual emotional stimuli. We predicted that OXY would decrease amygdala activity to negative stimuli and increase ventral striatum (VS) activity to positive stimuli. Secondarily, we examined the effects of OXY on other emotional network regions on an exploratory basis.
In a three-session study, healthy adults (N = 17) received placebo, 10 and 20 mg OXY under counterbalanced, double-blind conditions. At each session, participants completed subjective and cardiovascular measures and underwent functional MRI (fMRI) scanning while completing two emotional response tasks.
Our emotional tasks reliably activated emotional network areas. OXY produced subjective effects but did not alter either behavioral responses to emotional stimuli or activity in our primary areas of interest. OXY did decrease right medial orbitofrontal cortex (MOFC) responses to happy faces.
Contrary to our expectations, OXY did not affect behavioral or neural responses to emotional stimuli in our primary areas of interest. Further, the effects of OXY in the MOFC would be more consistent with a decrease in value for happy faces. This may indicate that healthy adults do not receive emotional benefits from opiates, or the pharmacological actions of OXY differ from other opiates.
来自动物和人体研究的证据表明，阿片类药物会降低对负面刺激的情绪反应，并增强对正面刺激的反应。这种情绪效应可能会促使人们滥用羟考酮（OXY），一种被广泛滥用的阿片类药物。然而，我们对OXY如何影响人类情绪处理的神经回路知之甚少。
我们研究了OXY对呈现正面和负面视觉情绪刺激时大脑活动的影响。我们预测，OXY会降低杏仁核对负面刺激的活动，并增加腹侧纹状体（VS）对正面刺激的活动。其次，我们在探索性基础上研究了OXY对其他情绪网络区域的影响。
在一项分三个阶段的研究中，17名健康成年人在平衡、双盲条件下接受安慰剂、10毫克和20毫克的OXY。在每个阶段，参与者完成主观和心血管测量，并在完成两项情绪反应任务时接受功能磁共振成像（fMRI）扫描。
我们的情绪任务可靠地激活了情绪网络区域。OXY产生了主观效应，但没有改变对情绪刺激的行为反应或我们主要感兴趣区域的活动。OXY确实降低了右侧内侧眶额皮质（MOFC）对笑脸的反应。
与我们的预期相反，OXY没有影响我们主要感兴趣区域对情绪刺激的行为或神经反应。此外，OXY在MOFC中的作用更符合笑脸价值的降低。这可能表明健康成年人无法从阿片类药物中获得情绪益处，或者OXY的药理作用与其他阿片类药物不同。
