Department of Psychology, Monash University, Clayton 3800, Victoria, Australia.
Psychiatry Res. 2009 Dec 30;174(3):210-6. doi: 10.1016/j.pscychresns.2009.06.001. Epub 2009 Nov 13.
Although post-traumatic stress disorder (PTSD) may be seen to represent a failure to extinguish learned fear, significant aspects of the pathophysiology relevant to this hypothesis remain unknown. Both the amygdala and hippocampus are necessary for fear extinction occur, and thus both regions may be abnormal in PTSD. Twenty-five people who experienced the Tokyo subway sarin attack in 1995, nine who later developed PTSD and 16 who did not, underwent magnetic resonance imaging (MRI) with manual tracing to determine bilateral amygdala and hippocampus volumes. At the time of scanning, one had PTSD and eight had a history of PTSD. Results indicated that the group with a history of PTSD had significantly smaller mean bilateral amygdala volume than did the group that did not develop PTSD. Furthermore, left amygdala volume showed a significant negative correlation with severity of PTSD symptomatology as well as reduced gray matter density in the left anterior cingulate cortex. To our knowledge, this is the first observation of an association between PTSD and amygdala volume. Furthermore the apparent interplay between amygdala and anterior cingulate cortex represents support at the level of gross brain morphology for the theory of PTSD as a failure of fear extinction.
虽然创伤后应激障碍（PTSD）可能被视为未能消除习得性恐惧，但与这一假设相关的重要病理生理学方面仍不清楚。杏仁核和海马体对于恐惧的消除都是必要的，因此这两个区域在 PTSD 中可能都不正常。1995 年，25 名经历过东京地铁沙林袭击的人接受了磁共振成像（MRI）手动追踪检查，以确定双侧杏仁核和海马体的体积。在扫描时，1 人患有 PTSD，8 人有 PTSD 病史。结果表明，有 PTSD 病史的组双侧杏仁核的平均体积明显小于未发展出 PTSD 的组。此外，左杏仁核体积与 PTSD 症状严重程度呈显著负相关，左前扣带回皮质的灰质密度也降低。据我们所知，这是首次观察到 PTSD 与杏仁核体积之间存在关联。此外，杏仁核和前扣带皮层之间的明显相互作用代表了在大体脑形态学水平上对 PTSD 作为恐惧消除失败理论的支持。
