Different methods of fear reduction are supported by distinct cortical substrates
Abstract
Understanding how learned fear can be reduced is at the heart of treatments for anxiety disorders. Tremendous progress has been made in this regard through extinction training in which the aversive outcome is omitted. However, current progress almost entirely rests on this single paradigm, resulting in a very specialized knowledgebase at the behavioural and neural level of analysis. Here, we used a dual-paradigm approach to show that different methods that lead to reduction in learned fear in rats are dissociated in the cortex. We report that the infralimbic cortex has a very specific role in fear reduction that depends on the omission of aversive events but not on overexpectation. The orbitofrontal cortex, a structure generally overlooked in fear, is critical for downregulating fear when novel predictions about upcoming aversive events are generated, such as when fear is inflated or overexpected, but less so when an expected aversive event is omitted.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for all figures.
Article and author information
Author details
Funding
Fonds de Recherche du Québec - Nature et Technologies (2017-NC-198182)
- Mihaela D Iordanova
Canadian Institutes of Health Research (Project Grant)
- Mihaela D Iordanova
Brain and Behavior Research Foundation (NARSAD grant)
- Mihaela D Iordanova
Canada Research Chairs
- Mihaela D Iordanova
Fonds de Recherche du Québec - Santé
- Belinda PP Lay
Natural Sciences and Engineering Research Council of Canada
- Nathan Boulianne
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All experimental procedures were in accordance with the approval granted by the Canadian Council on Animal Care and the Concordia University Animal Care Committee.
Copyright
© 2020, Lay et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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