Utz A, Thürling M, Ernst T M, Hermann A, Stark R, Wolf O T, Timmann D, Merz C J
Department of Neurology, University Clinic Essen, University of Duisburg-Essen, Hufelandstrasse 55, 45147 Essen, Germany.
Department of Psychotherapy and Systems Neuroscience and Bender Institute of Neuroimaging, Justus Liebig University Giessen, Otto-Behaghel-Str. 10H, 35394 Giessen, Germany.
Neurosci Lett. 2015 Sep 14;604:173-7. doi: 10.1016/j.neulet.2015.07.026. Epub 2015 Jul 26.
The cerebellum is known to contribute to the acquisition and retention of conditioned motor and emotional responses. Eyeblink conditioning and fear conditioning have been studied in greatest detail. Whereas a considerable number of studies have shown that the cerebellum is also involved in extinction of conditioned eyeblink responses, the likely contribution of the cerebellum to extinction of conditioned fear responses has largely been ignored. In the present study, we analyzed functional brain imaging data (fMRI) of previous work investigating extinction of conditioned fear in 32 young and healthy men, in which event-related fMRI analysis did not include the cerebellum. This dataset was analyzed using a spatial normalization method optimized for the cerebellum. During fear acquisition, an unpleasant electric shock (unconditioned stimulus; US) was paired with one of two pictures of geometrical figures (conditioned stimulus; CS+), while the other picture (CS-) was never paired with the US. During extinction, CS+ and CS- were presented without the US. During the acquisition phase, the fMRI signal related to the CS+ was significantly higher in hemispheric lobule VI in early compared to late acquisition (p<.05, permutation corrected). During the extinction phase, the fMRI signal related to the contrast CS+>CS- was significantly higher within the anterior vermis in early compared to late extinction (p<.05, permutation corrected). The present data show that the cerebellum is not only associated with the acquisition but also with the extinction of conditioned fear.
已知小脑有助于习得和保留条件性运动和情绪反应。眨眼条件反射和恐惧条件反射的研究最为详尽。尽管大量研究表明小脑也参与条件性眨眼反应的消退，但小脑对条件性恐惧反应消退的可能作用在很大程度上被忽视了。在本研究中，我们分析了之前一项针对32名年轻健康男性的条件性恐惧消退研究的功能性脑成像数据（功能磁共振成像），该研究的事件相关功能磁共振成像分析未包括小脑。使用针对小脑优化的空间归一化方法对该数据集进行分析。在恐惧习得过程中，将不愉快的电击（非条件刺激；US）与两张几何图形图片之一（条件刺激；CS+）配对，而另一张图片（CS-）从未与US配对。在消退过程中，呈现CS+和CS-时不给予US。在习得阶段，与CS+相关的功能磁共振成像信号在早期半球小叶VI中显著高于后期习得（p<.05，经置换校正）。在消退阶段，与CS+>CS-对比相关的功能磁共振成像信号在早期蚓部前部显著高于后期消退（p<.05，经置换校正）。目前的数据表明，小脑不仅与条件性恐惧的习得有关，还与条件性恐惧的消退有关。
