Lissek Silke, Glaubitz Benjamin, Wolf Oliver T, Tegenthoff Martin
Department of Neurology, BG University Hospital Bergmannsheil, Ruhr-University Bochum Bochum, Germany.
Department of Cognitive Psychology, Faculty of Psychology, Institute for Cognitive Neuroscience, Ruhr-University Bochum Bochum, Germany.
Front Behav Neurosci. 2015 Sep 3;9:238. doi: 10.3389/fnbeh.2015.00238. eCollection 2015.
Renewal describes the recovery of an extinguished response if recall is tested in a context different from the extinction context. Behavioral studies demonstrated that attention to relevant context strengthens renewal. Neurotransmitters mediating attention and learning such as the dopaminergic (DA) system presumably modulate extinction learning and renewal. However, the role of DA for non-fear-based extinction learning and renewal in humans has not yet been investigated. This fMRI study investigated effects of DA-antagonism upon context-related extinction in a predictive learning task in which extinction occurred either in a novel (ABA) or an unchanged (AAA) context. The tiapride-treated group (TIA) showed significantly impaired ABA extinction learning and a significant within-group difference between ABA and AAA extinction, compared to placebo (PLAC). Groups did not differ in their level of ABA renewal. In ABA extinction, TIA showed reduced activation in dlPFC and OFC, hippocampus, and temporal regions. Across groups, activation in PFC and hippocampus correlated negatively with ABA extinction errors. Results suggest that in context-related extinction learning DA in PFC and hippocampus is involved in readjusting the cue-outcome relationship in the presence of a novel context. However, relating context to the appropriate association during recall does not appear to rely exclusively on DA signaling.
恢复现象是指，如果在与消退情境不同的背景下进行回忆测试，已消退的反应会重新出现。行为学研究表明，对相关背景的关注会增强恢复现象。诸如多巴胺能（DA）系统等介导注意力和学习的神经递质，可能会调节消退学习和恢复现象。然而，DA在人类非恐惧性消退学习和恢复现象中的作用尚未得到研究。这项功能磁共振成像（fMRI）研究，在一个预测性学习任务中，探究了DA拮抗作用对与背景相关的消退的影响，在该任务中，消退分别发生在新背景（ABA）或不变背景（AAA）下。与安慰剂组（PLAC）相比，硫必利治疗组（TIA）在ABA情境下的消退学习显著受损，且ABA和AAA消退之间存在显著的组内差异。两组在ABA恢复水平上没有差异。在ABA消退过程中，TIA在背外侧前额叶皮质（dlPFC）、眶额皮质（OFC）、海马体和颞叶区域的激活减少。在所有组中，前额叶皮质和海马体的激活与ABA消退错误呈负相关。结果表明，在与背景相关的消退学习中，前额叶皮质和海马体中的DA参与了在新背景下重新调整线索-结果关系。然而，在回忆过程中将背景与适当的关联联系起来，似乎并不完全依赖于DA信号传导。
