Department of Psychology, University of Freiburg, D-79104 Freiburg, Germany.
Psychoneuroendocrinology. 2010 Jan;35(1):83-93. doi: 10.1016/j.psyneuen.2009.06.016.
The neuropeptide oxytocin (OXT) has previously been found to reduce amygdala reactivity to social and emotional stimuli in healthy men. The present study aimed to investigate the effect of intranasally administered OXT on brain activity in response to social emotional stimuli of varying valence in women. In a functional magnetic-resonance imaging study, sixteen women were presented with fearful, angry, happy and neutral facial expressions after a single dose of 24IU OXT or a placebo administration in a within-subject design. Group analysis revealed that the blood-oxygen-level-dependent (BOLD) signal was enhanced in the left amygdala, the fusiform gyrus and the superior temporal gyrus in response to fearful faces and in the inferior frontal gyrus in response to angry and happy faces following OXT treatment. This effect was independent of fixation pattern to specific sections of the facial stimuli as revealed by eye tracking and independent of basal plasma levels of OXT, estradiol, and progesterone. The results are at odds with the previously reported effects found in men. Future studies should include both sexes to determine a possible sexual dimorphism in the neural effects of OXT, considering gonadal steroids and OXT receptor affinity.
神经肽催产素（OXT）先前已被发现可降低健康男性对社交和情绪刺激的杏仁核反应性。本研究旨在探究鼻内给予 OXT 对女性对不同效价的社交情绪刺激的大脑活动的影响。在一项功能磁共振成像研究中，16 名女性在单次给予 24IU OXT 或安慰剂后，以 24IU OXT 或安慰剂在一个被试内设计中呈现恐惧、愤怒、快乐和中性面部表情。组分析显示，与安慰剂相比，OXT 治疗后，左杏仁核、梭状回和颞上回对恐惧面孔的血氧水平依赖（BOLD）信号增强，下额叶回对愤怒和快乐面孔的 BOLD 信号增强。这种效应独立于眼动追踪显示的对特定面部刺激区域的注视模式，也独立于基础血浆 OXT、雌二醇和孕酮水平。该结果与先前在男性中发现的效应相矛盾。未来的研究应包括两性，以确定 OXT 的神经效应中可能存在的性别二态性，同时考虑到性腺类固醇和 OXT 受体亲和力。
