Abstract
Rodent research indicates that acute physical exercise facilitates fear learning and inhibition. Expression of brain-derived neurotrophic factor (BDNF) may moderate the memory enhancing effects of acute exercise. We assessed the role of acute exercise in modulating extinction retention in humans, and investigated the extent to which the BDNF polymorphism influenced extinction retention. Seventy non-clinical participants engaged in a differential fear potentiated startle paradigm involving conditioning and extinction followed by random assignment to either intense exercise (n = 35) or no exercise (n = 35). Extinction retention was assessed 24 h later. Saliva samples were collected to index BDNF genotype. Exercised participants displayed significantly lower fear 24 h later relative to non-exercised participants. Moderation analyses indicated that after controlling for gender, the BDNF Val66Met polymorphism moderated the relationship between exercise and fear recovery 24 h later, such that exercise was associated with greater fear recovery in individuals with the Met allele. These findings provide initial evidence that acute exercise can impact fear extinction in humans and this effect is reduced in Met-allele carriers. This finding accords with the role of BDNF in extinction learning, and has implications for augmenting exposure-based therapies for anxiety disorders.
Highlights
Fear extinction is a form of inhibitory associative learning whereby a previously conditioned stimulus (CS) becomes associated with safety via repeated exposure to it in the absence of an aversive outcome[1]
We aimed to examine the effect of an acute bout of exercise in modulating extinction retention
Maximum heart rate data was missing for 14 exercised and 16 non-exercised participants due to technical difficulties, and as such were replaced with the mean for the respective group
Summary
Fear extinction is a form of inhibitory associative learning whereby a previously conditioned stimulus (CS) becomes associated with safety via repeated exposure to it in the absence of an aversive outcome[1]. This new safety memory competes with the original fear conditioned memory, such that under certain conditions it can function to actively inhibit fear expression[2]. Fear extinction forms the basis of exposure therapy for anxiety-related disorders. Despite strong empirical validation for exposure therapy[3,4], many individuals do not optimally benefit from this treatment and this has prompted an exploration of ways to enhance retention of fear extinction.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
