Positron emission tomographic imaging of neural correlates of a fear acquisition and extinction paradigm in women with childhood sexual-abuse-related post-traumatic stress disorder
Positron emission tomographic imaging of neural correlates of a fear acquisition and extinction paradigm in women with childhood sexual-abuse-related post-traumatic stress disorder
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DOI：
10.1017/s0033291704003290
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发表时间：
2005-06-01
影响因子：
6.9
通讯作者：
Charney, DS
中科院分区：
文献类型：
--
作者：
Bremner, JD;Vermetten, E;Charney, DS
背景在条件恐惧范式中，厌恶性非条件刺激（US）（例如电击）与中性条件刺激（CS）（例如亮光）的重复配对导致对单独的光的条件恐惧反应。动物研究表明，杏仁核在条件性恐惧反应的获得中起着关键作用，而内侧前额叶皮层（包括前扣带回）通过抑制杏仁核反应，被假设在恐惧反应的消退中起作用。没有研究探讨创伤后应激障碍（PTSD）患者恐惧条件反射和消退的神经相关性。患有早期儿童性虐待相关PTSD的妇女（n = 8）和没有虐待或PTSD的妇女（n = 11）在习惯化、获得和消退条件下进行了心理生理（皮肤电导）反应测量以及脑血流量的正电子发射断层扫描（PET）测量。在习惯化过程中，受试者反复暴露在屏幕上的蓝色方块中。在采集过程中，暴露于蓝色方块（CS）与前臂电击（US）配对。在熄灭的情况下，受试者再次暴露在蓝色方块中，没有电击。在另一天，受试者经历了相同的程序，在没有蓝色方块的情况下随机给予电击。皮肤电导响应CS是一致的条件反射的发展与此范例。与对照组相比，PTSD患者在获得恐惧时左杏仁核激活增加，在消退时前扣带回功能降低。这些发现暗示杏仁核和前扣带回在获得和消除恐惧反应，分别在创伤后应激障碍。
Background. In the conditioned fear paradigm, repeated pairing of an aversive unconditioned stimulus (US) (e.g. electric shock) with a neutral conditioned stimulus (CS) (e.g. bright light) results in a conditioned fear response to the light alone. Animal studies have shown that the amygdala plays a critical role in acquisition of conditioned fear responses, while the medial prefrontal cortex (including anterior cingulate), through inhibition of amygdala responsiveness, has been hypothesized to play a role in extinction of fear responses. No studies have examined neural correlates of fear conditioning and extinction in patients with post-traumatic stress disorder (PTSD).Method. Women with early childhood sexual-abuse-related PTSD (n = 8) and women without abuse or PTSD (n = 11) underwent measurement of psychophysiological (skin conductance) responding as well as positron emission tomographic (PET) measurement of cerebral blood flow during habituation, acquisition and extinction conditions. During habituation subjects were repeatedly exposed to a blue square on a screen. During acquisition, exposure to the blue square (CS) was paired with an electric shock to the forearm (US). With extinction, subjects were again exposed to the blue squares without shock. On a different day subjects went through the same procedure with electric shocks administered randomly in the absence of the blue square.Results. Skin conductance responding to the CS was consistent with the development of conditioned responses with this paradigm. PTSD patients had increased left amygdala activation with fear acquisition, and decreased anterior cingulate function during extinction, relative to controls.Conclusions. These findings implicate amygdala and anterior cingulate in the acquisition and extinction of fear responses, respectively, in PTSD.