Boston College, Department of Psychology & Neuroscience, Chestnut Hill, MA, USA.
Tufts University School of Medicine, School of Graduate Biomedical Sciences, Boston, MA, USA.
Behav Brain Res. 2021 Feb 5;399:112974. doi: 10.1016/j.bbr.2020.112974. Epub 2020 Nov 2.
Animals organize reward seeking around aversive events. An abundance of research shows that foot shock, as well as a shock-associated cue, can elicit freezing and suppress reward seeking. Yet, there is evidence that experience can flip the effect of foot shock to facilitate reward seeking. Here we examined cue suppression, foot shock suppression and foot shock facilitation of reward seeking in a single behavioural setting. Male Long Evans rats received fear discrimination consisting of danger, uncertainty, and safety cues. Discrimination took place over a baseline of rewarded nose poking. With limited experience (1-2 sessions), all cues and foot shock suppressed reward seeking. With continued experience (10-16 sessions), suppression became specific to shock-associated cues, foot shock briefly suppressed, then facilitated reward seeking. Our results provide a means of assessing positive properties of foot shock, and may provide insight into maladaptive behaviour around aversive events.
动物会围绕令人不快的事件组织奖励寻求。大量研究表明,足底电击以及与电击相关的线索可以引起冻结并抑制奖励寻求。然而,有证据表明,经验可以翻转足底电击的效果,促进奖励寻求。在这里,我们在单一行为环境中检查了线索抑制、足底电击抑制和足底电击促进奖励寻求的效果。雄性长耳大仓鼠接受了由危险、不确定和安全线索组成的恐惧辨别训练。辨别训练在奖励性鼻探测的基础上进行。在有限的经验(1-2 个疗程)中,所有线索和足底电击都抑制了奖励寻求。随着经验的不断增加(10-16 个疗程),抑制变得专门针对与电击相关的线索,足底电击短暂抑制,然后促进奖励寻求。我们的结果提供了一种评估足底电击积极属性的方法,并可能为理解围绕不愉快事件的适应不良行为提供线索。