Unconditioned response to an aversive stimulus as predictor of response to conditioned fear and safety: A cross-species study.

Abstract

Safety signals predict the non-occurrence of an aversive event, thereby inhibiting fear responses. Previous research has shown that conditioned safety learning is impaired in patients suffering from post-traumatic stress disorder (PTSD). Using a translational approach, the present study aimed to investigate whether individual responses to an aversive unconditioned stimulus (US) in rats (basic science), non-traumatized (pre-clinical) or traumatized humans (clinical) predicts their response to a conditioned fear or safety stimulus. Using three different archival datasets, the unconditioned response (UCR) to the US during fear or safety conditioning was assessed in rats, non-traumatized humans, and trauma-exposed humans. The response to learned fear (CS+; context) and safety (CS-) was measured by the modulation of the startle response (rats, traumatized humans) or skin conductance response (non-traumatized humans). Our results showed that all groups with low UCR and those with high UCR from the rodent or non-traumatized human samples displayed lower fear response to the CS- than to the CS+ . Traumatized humans with high UCR showed similarly high responses to the CS+ and CS-. While all groups showed a positive association between the UCR and CS+ response, the UCR correlated positively with the CS- response in traumatized humans only. Our findings suggest that an elevated response to aversive stimuli predicts deficits in conditioned safety memory in those at risk for trauma-related disorders and confirms that impaired safety learning could be a valid biomarker for these diseases.

• Authors: Judith C Kreutzmann, Marie-France Marin, Markus Fendt, Mohammed R Milad, Kerry Ressler, Tanja Jovanovic
• Journal: Behavioural brain research (Behav Brain Res) Vol. 402 Pg. 113105 (03 26 2021) ISSN: 1872-7549 [Electronic] Netherlands
• PMID: 33417995 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2021 Elsevier B.V. All rights reserved.

Topics

• Adolescent
• Adult
• Animals
• Anxiety (physiopathology)
• Behavior, Animal (physiology)
• Conditioning, Classical (physiology)
• Fear (physiology)
• Female
• Galvanic Skin Response (physiology)
• Humans
• Male
• Middle Aged
• Psychological Trauma (physiopathology)
• Rats
• Rats, Sprague-Dawley
• Reflex, Startle (physiology)
• Safety
• Stress Disorders, Post-Traumatic (physiopathology)
• Young Adult