title: A Stress-Induced Shift From Trace to Delay Conditioning Depends on the Mineralocorticoid Receptor.
abstract: BACKGROUND
  Fear learning in stressful situations is highly adaptive for survival by steering behavior in subsequent situations, but fear learning can become disproportionate in vulnerable individuals. Despite the potential clinical significance, the mechanism by which stress modulates fear learning is poorly understood. Memory theories state that stress can cause a shift away from more controlled processing depending on the hippocampus toward more reflexive processing supported by the amygdala and striatum. This shift may be mediated by activation of the mineralocorticoid receptor (MR) for cortisol. We investigated how stress shifts processes underlying cognitively demanding learning versus less demanding fear learning using a combined trace and delay fear conditioning paradigm.
  
  
  METHODS
  In a pharmacological functional magnetic resonance imaging study, we tested 101 healthy men probing the effects of stress (socially evaluated cold pressor vs. control procedure) and MR-availability (400 mg spironolactone vs. placebo) in a randomized, placebo-controlled, full-factorial, between-subjects design.
  
  
  RESULTS
  Effective stress induction and successful conditioning were confirmed by subjective, physiologic, and somatic data. In line with a stress-induced shift, stress enhanced later recall of delay compared with trace conditioning in the MR-available groups as indexed by skin conductance responses. During learning, this was accompanied by a stress-induced reduction of learning-related hippocampal activity for trace conditioning. The stress-induced shift in fear and neural processing was absent in the MR-blocked groups.
  
  
  CONCLUSIONS
  Our results are in line with a stress-induced shift in fear learning, mediated by the MR, resulting in a dominance of cognitively less demanding amygdala-based learning, which might be particularly prominent in individuals with high MR sensitivity.
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour; Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen. Electronic address: s.vogel@donders.ru.nl.
authors.forename: Susanne
authors.initials: S
authors.lastname: Vogel
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour; Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen.
authors.forename: Floris
authors.initials: F
authors.lastname: Klumpers
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour.
authors.forename: Marijn C W
authors.initials: MC
authors.lastname: Kroes
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour.
authors.forename: Krista T
authors.initials: KT
authors.lastname: Oplaat
authors.affiliation: Faculty of Science, University of Amsterdam, Amsterdam.
authors.forename: Harm J
authors.initials: HJ
authors.lastname: Krugers
authors.affiliation: Faculty of Science, University of Amsterdam, Amsterdam.
authors.forename: Melly S
authors.initials: MS
authors.lastname: Oitzl
authors.affiliation: Rudolf Magnus Institute of Neuroscience, Utrecht, The Netherlands.
authors.forename: Marian
authors.initials: M
authors.lastname: Joëls
authors.affiliation: Donders Institute for Brain, Cognition and Behaviour; Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen.
authors.forename: Guillén
authors.initials: G
authors.lastname: Fernández
mesh_terms: D000328:Adult; D000679:Amygdala / Q000187:drug effects / Q000503:physiopathology*; D001931:Brain Mapping; D003080:Cold Temperature; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D004311:Double-Blind Method; D005239:Fear / Q000187:drug effects / Q000502:physiology*; D005712:Galvanic Skin Response; D006624:Hippocampus / Q000187:drug effects / Q000503:physiopathology*; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D011939:Mental Recall / Q000187:drug effects / Q000502:physiology; D018161:Receptors, Mineralocorticoid / Q000819:agonists / Q000502:physiology*; D013148:Spironolactone / Q000494:pharmacology; D013315:Stress, Psychological / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D018161:Receptors, Mineralocorticoid; D013148:Spironolactone; D006854:Hydrocortisone
keywords: Amygdala; Fear; Hippocampus; Memory systems; Mineralocorticoid receptor; Stress