P28-T Temporary changes of resting-state functional networks after fear learning

Abstract

Introduction Resting-state functional connectivity (rsFC) may indicate abnormalities in the brain physiology as it was shown at the example of altered rsFC within fear-processing brain circuit in patients with posttraumatic stress disorder. However, little is known about whether resting state networks vary their functional connections after experimental fear learning (FL). Here, we studied brain network changes in the resting state immediately, in one day and a week after FL using graph theory metrics. Methods We collected resting state fMRI data from 19 healthy controls and 24 healthy participants of FL protocol. Control group underwent three fMRI sessions: the second and the third sessions took place in one day and a week after the first respectively. FL group underwent five sessions: before FL, with fear memory retrieval, after FL, one day after, and a week after the first. We calculated paired FC of 94 anatomical regions of interest and analyze graph theory metrics of reconstructed networks for each session. Results The network during fear memory retrieval showed greater global efficiency than other resting state networks. Bilateral middle frontal gyri and parietal lobes became and remained network hubs after FL as well as in one day and one week afterward. No significant network changes were observed in the control group. Discussion and conclusions Our findings highlight the temporary effect of FL at resting state networks, which implies the functional readjustment of neural connections even after mild aversive exposure. This study was funded by the Grant No. 16-15-00300 of the Russian Scientific Foundation .