LaBar K S, Gatenby J C, Gore J C, LeDoux J E, Phelps E A
Department of Psychology, Yale University, New Haven, Connecticut 06520, USA.
Neuron. 1998 May;20(5):937-45. doi: 10.1016/s0896-6273(00)80475-4.
Echoplanar functional magnetic resonance imaging (fMRI) was used in normal human subjects to investigate the role of the amygdala in conditioned fear acquisition and extinction. A simple discrimination procedure was employed in which activation to a visual cue predicting shock (CS+) was compared with activation to another cue presented alone (CS-). CS+ and CS- trial types were intermixed in a pseudorandom order. Functional images were acquired with an asymmetric spin echo pulse sequence from three coronal slices centered on the amygdala. Activation of the amygdala/periamygdaloid cortex was observed during conditioned fear acquisition and extinction. The extent of activation during acquisition was significantly correlated with autonomic indices of conditioning in individual subjects. Consistent with a recent electrophysiological recording study in the rat (Quirk et al., 1997), the profile of the amygdala response was temporally graded, although this dynamic was only statistically reliable during extinction. These results provide further evidence for the conservation of amygdala function across species and implicate an amygdalar contribution to both acquisition and extinction processes during associative emotional learning tasks.
利用回波平面功能磁共振成像（fMRI）对正常人类受试者进行研究，以探讨杏仁核在条件性恐惧习得和消退中的作用。采用了一种简单的辨别程序，将对预测电击的视觉线索（CS+）的激活与对单独呈现的另一个线索（CS-）的激活进行比较。CS+和CS-试验类型以伪随机顺序混合。使用不对称自旋回波脉冲序列从以杏仁核为中心的三个冠状切片采集功能图像。在条件性恐惧习得和消退过程中观察到杏仁核/杏仁核周围皮质的激活。习得过程中的激活程度与个体受试者的条件反射自主指标显著相关。与最近在大鼠身上进行的一项电生理记录研究（Quirk等人，1997年）一致，杏仁核反应的特征在时间上是分级的，尽管这种动态变化仅在消退过程中具有统计学可靠性。这些结果为跨物种杏仁核功能的保守性提供了进一步的证据，并表明杏仁核在联想性情绪学习任务的习得和消退过程中均有贡献。
