Lang Simone, Kroll Alexander, Lipinski Slawomira J, Wessa Michèle, Ridder Stephanie, Christmann Christoph, Schad Lothar R, Flor Herta
Department of Clinical and Cognitive Neuroscience, Central Institute of Mental Health, University of Heidelberg, Mannheim, Germany.
Eur J Neurosci. 2009 Feb;29(4):823-32. doi: 10.1111/j.1460-9568.2009.06624.x. Epub 2008 Feb 6.
Functional magnetic resonance imaging was used to investigate the role of the hippocampus, amygdala and medial prefrontal cortex (mPFC) in a contextual conditioning and extinction paradigm provoking anxiety. Twenty-one healthy persons participated in a differential context conditioning procedure with two different background colours as contexts. During acquisition increased activity to the conditioned stimulus (CS+) relative to the CS- was found in the left hippocampus and anterior cingulate cortex (ACC). The amygdala, insula and inferior frontal cortex were differentially active during late acquisition. Extinction was accompanied by enhanced activation to CS+ vs. CS- in the dorsal anterior cingulate cortex (dACC). The results are in accordance with animal studies and provide evidence for the important role of the hippocampus in contextual learning in humans. Connectivity analyses revealed correlated activity between the left posterior hippocampus and dACC (BA32) during early acquisition and the dACC, left posterior hippocampus and right amygdala during extinction. These data are consistent with theoretical models that propose an inhibitory effect of the mPFC on the amygdala. The interaction of the mPFC with the hippocampus may reflect the context-specificity of extinction learning.
功能磁共振成像被用于研究海马体、杏仁核和内侧前额叶皮质（mPFC）在引发焦虑的情境条件作用和消退范式中的作用。21名健康受试者参与了一项以两种不同背景颜色作为情境的差异情境条件作用程序。在习得过程中，相对于条件刺激（CS-），左侧海马体和前扣带回皮质（ACC）对条件刺激（CS+）的活动增加。在习得后期，杏仁核、脑岛和额下回表现出不同程度的活跃。消退过程中，背侧前扣带回皮质（dACC）对CS+相对于CS-的激活增强。这些结果与动物研究一致，并为海马体在人类情境学习中的重要作用提供了证据。连通性分析显示，在习得早期，左侧后海马体与dACC（BA32）之间存在相关活动，在消退过程中，dACC、左侧后海马体与右侧杏仁核之间存在相关活动。这些数据与提出mPFC对杏仁核具有抑制作用的理论模型一致。mPFC与海马体之间的相互作用可能反映了消退学习的情境特异性。
