A Mouse Model of Stress-Enhanced Fear Learning Demonstrates Extinction-Sensitive and Extinction-Resistant Effects of Footshock Stress.

A Mouse Model of Stress-Enhanced Fear Learning Demonstrates Extinction-Sensitive and Extinction-Resistant Effects of Footshock Stress. Behav Brain Res. 2019 Nov 27;:112391 Authors: Hassien AM, Shue F, Bernier BE, Drew MR Abstract Stressful experiences ca cause long-lasting sensitization of fear and anxiety that extends beyond the circumstances of the initial trauma. The neural mechanisms of these stress effects have been studied extensively in rats using the stress-enhanced fear learning (SEFL) paradigm, in which exposure to footshock stress potentiates subsequent fear conditioning. Here we establish a mouse version of the SEFL. Male and female 129s6 mice received four 1-mA foot shocks or equivalent context exposure without shock. Shock exposure induced Pavlovian fear conditioning to the shock context and produced three more general effects: (1) suppression of open field exploration, (2) potentiated unconditioned fear of a novel tone stimulus, and (3) enhanced fear conditioning in a novel context. To determine whether these effects of footshock stress reflect generalized Pavlovian fear conditioning versus nonassociative fear sensitization, some mice received extinction training in the footshock stress context, which reduced contextual fear to the levels of unstressed control mice. Extinction restored normal open field exploration, suggesting that this effect of stress reflects generalized Pavlovian fear. In contrast, extinction faile...
Source: Behavioural Brain Research - Category: Neurology Authors: Tags: Behav Brain Res Source Type: research