Voluntary exercise does not ameliorate context memory and hyperarousal in a mouse model for post-traumatic stress disorder (PTSD).

Abstract

OBJECTIVES: We investigated the effects of voluntary wheel running as model for intervention on the development of contextual fear and hyperarousal in a mouse model of post-traumatic stress disorder (PTSD). Physical exercise in general has been associated with improved hippocampus-dependent memory performance both in animals and humans. However, studies that have tried to link physical exercise and contextual conditioning in an animal model of PTSD, revealed mixed findings. METHODS: Here we tested contextual fear conditioning, generalized fear response, acoustic startle response and emotionality in C57BL/6NCrl mice which had free access to a running wheel for 28 days, compared with control animals which did not run and mice which did not receive a shock during the conditioning phase. RESULTS: We found no significant effects of voluntary running on the above-mentioned variables, except for enhanced anxiety levels in the Dark-Light-Box and O-Maze tests of running mice. CONCLUSIONS: Our results suggest that running as a model for intervention does not ameliorate contextual aversive learning but has the potency to change emotional behaviours.