Department of Psychiatry, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Neuroscientist. 2009 Oct;15(5):540-8. doi: 10.1177/1073858409333072. Epub 2009 Apr 9.
Posttraumatic stress disorder (PTSD) is characterized by recurrent distressing memories of an emotionally traumatic event. In this review, the authors present neuroscientific data highlighting the function of two brain areas--the amygdala and ventromedial prefrontal cortex (vmPFC)--in PTSD and related emotional processes. A convergent body of human and nonhuman studies suggests that the amygdala mediates the acquisition and expression of conditioned fear and the enhancement of emotional memory, whereas the vmPFC mediates the extinction of conditioned fear and the volitional regulation of negative emotion. It has been theorized that the vmPFC exerts inhibition on the amygdala, and that a defect in this inhibition could account for the symptoms of PTSD. This theory is supported by functional imaging studies of PTSD patients, who exhibit hypoactivity in the vmPFC but hyperactivity in the amygdala. A recent study of brain-injured and trauma-exposed combat veterans confirms that amygdala damage reduces the likelihood of developing PTSD. But contrary to the prediction of the top-down inhibition model, vmPFC damage also reduces the likelihood of developing PTSD. The putative roles of the amygdala and the vmPFC in the pathophysiology of PTSD, as well as implications for potential treatments, are discussed in light of these results.
创伤后应激障碍（PTSD）的特征是反复出现对情绪创伤性事件的痛苦记忆。在这篇综述中，作者提出了神经科学数据，强调了两个大脑区域——杏仁核和腹内侧前额叶皮层（vmPFC）——在 PTSD 和相关情绪过程中的作用。大量的人类和非人类研究表明，杏仁核介导条件性恐惧的获得和表达，以及情绪记忆的增强，而 vmPFC 则介导条件性恐惧的消退和负性情绪的意志调节。理论上认为 vmPFC 对杏仁核施加抑制，而这种抑制的缺陷可能是 PTSD 症状的原因。这一理论得到了 PTSD 患者功能成像研究的支持，这些患者的 vmPFC 活动减少，而杏仁核活动增加。最近一项对脑损伤和创伤暴露的战斗退伍军人的研究证实，杏仁核损伤降低了 PTSD 的发病几率。但与自上而下的抑制模型的预测相反，vmPFC 损伤也降低了 PTSD 的发病几率。鉴于这些结果，讨论了杏仁核和 vmPFC 在 PTSD 病理生理学中的可能作用，以及对潜在治疗方法的影响。
