Department of Biomedical Engineering, School of Science and Engineering, Reykjavik University, Reykjavik, Iceland.
Neuroimage. 2010 May 15;51(1):324-8. doi: 10.1016/j.neuroimage.2010.02.029. Epub 2010 Feb 13.
In spite of long-standing evidence showing that the hypothalamus is instrumental in generating behaviors associated with positive and negative emotions, little is known about the role of the hypothalamus in normal human emotional processing. Recent findings have suggested that the hypothalamus plays a role beyond mere control of HPA-axis function; this is also supported by the existence of rich anatomical connections between the hypothalamus and the amygdala, a region known for its important role in emotional processing. However, evidence of emotion-induced hypothalamic activity from neuroimaging studies has been inconsistent, possibly due to methodological limitations (e.g., low spatial resolution). Taking advantage of recent improvements in fMRI technology we set out to explore a possible valence-dependent modulation of hypothalamic activity. Using second order parametric analysis of high-resolution BOLD fMRI, we assessed hypothalamic activation patterns during passive viewing of visual stimuli of varying valence, and compared the results with the activity pattern in the amygdalae, i.e. nuclei with known valence-dependent activity profiles. We show that both hypothalamic and amygdalar activation is modulated by the second-order stimulus valence term, i.e., there is increased neural activity following the processing of both positive and negative stimuli. Our results suggest that the hypothalamus may serve a role in generating emotions broader than generally assumed.
尽管有长期的证据表明下丘脑在产生与积极和消极情绪相关的行为方面起着重要作用，但对于下丘脑在正常人类情绪处理中的作用知之甚少。最近的发现表明，下丘脑的作用不仅仅是控制 HPA 轴功能；这也得到了下丘脑和杏仁核之间丰富的解剖连接的支持，杏仁核是已知在情绪处理中起重要作用的区域。然而，神经影像学研究中关于情绪诱导的下丘脑活动的证据一直不一致，这可能是由于方法学上的限制（例如，空间分辨率低）。利用功能磁共振成像技术的最新进展，我们着手探索下丘脑活动可能存在的与效价相关的调节。使用高分辨率 BOLD fMRI 的二阶参数分析，我们评估了在被动观看不同效价的视觉刺激时下丘脑的激活模式，并将结果与杏仁核的活动模式进行了比较，即具有已知效价相关活动模式的核团。我们表明，下丘脑和杏仁核的激活都受到二阶刺激效价项的调节，即处理正性和负性刺激后都会增加神经活动。我们的结果表明，下丘脑在产生情绪方面的作用可能比普遍认为的更为广泛。
