Department of Psychology-Biological Psychology, Clinical Psychology, and Psychotherapy, University of Würzburg, Marcusstr 9-11, 97070 Wurzburg, Germany.
Psychopharmacology (Berl). 2012 Dec;224(4):573-9. doi: 10.1007/s00213-012-2785-y. Epub 2012 Jul 10.
The endocannabinoid (eCB) system is implicated in several psychiatric disorders. Investigating emotional-motivational dysfunctions as underlying mechanisms, a study in humans revealed that in the C385A polymorphism of the fatty acid amide hydrolase (FAAH), the degrading enzyme of the eCB anandamide (AEA), A carriers, who are characterized by increased signaling of AEA as compared to C/C carriers, exhibited reduced brain reactivity towards unpleasant faces and enhanced reactivity towards reward. However, the association of eCB system with emotional-motivational reactivity is complex and bidirectional due to upcoming compensatory processes.
Therefore, we further investigated the relationship of the FAAH polymorphism and emotional-motivational reactivity in humans.
We assessed the affect-modulated startle, and ratings of valence and arousal in response to higher arousing pleasant, neutral, and unpleasant pictures in 67 FAAH C385A C/C carriers and 45 A carriers.
Contrarily to the previous functional MRI study, A carriers compared to C/C carriers exhibited an increased startle potentiation and therefore emotional responsiveness towards unpleasant picture stimuli and reduced startle inhibition indicating reduced emotional reactivity in response to pleasant pictures, while both groups did not differ in ratings of arousal and valence.
Our findings emphasize the bidirectionality and thorough examination of the eCB system's impact on emotional reactivity as a central endophenotype underlying various psychiatric disorders.
内源性大麻素（eCB）系统与多种精神疾病有关。研究表明，情绪动机功能障碍是其潜在的发病机制之一。在一项人类研究中发现，脂肪酸酰胺水解酶（FAAH）的 C385A 多态性（eCB 降解酶，大麻素的降解酶）中，A 等位基因携带者与 C/C 携带者相比，AEA（内源性大麻素）信号转导增强，对不愉快面孔的大脑反应性降低，对奖赏的反应性增强。然而，由于即将出现的代偿过程，eCB 系统与情绪动机反应之间的关系是复杂和双向的。
因此，我们进一步研究了 FAAH 多态性与人类情绪动机反应之间的关系。
我们评估了 67 名 FAAH C385A C/C 携带者和 45 名 A 携带者在观看更高唤醒的愉快、中性和不愉快图片时，情绪调节的惊吓反射，以及对愉悦、中性和不愉快图片的效价和唤醒评分。
与之前的功能磁共振成像研究相反，与 C/C 携带者相比，A 携带者的惊吓反射增强，因此对不愉快图片的情绪反应性增强，对愉快图片的惊吓抑制反应性降低，而两组在唤醒和效价评分上没有差异。
我们的研究结果强调了 eCB 系统对情绪反应性的双向影响，并强调了对作为各种精神疾病潜在中枢表型的情绪反应性进行彻底研究的必要性。
