Rapid volumetric brain changes after acute psychosocial stress

Rapid structural brain plasticity after acute stress has been shown in animals. It is unknown whether such stress-related brain changes also occur in humans, in which they have been found, using structural magnetic resonance imaging (MRI), after motor learning and visual stimulation. We here investigated grey matter volume (GMV) changes after acute stress in humans and tested their relation to psychophysiological stress measures. Sixty-seven healthy men (25.8 +/- 2.7 years) completed a standardized psychosocial laboratory stressor (Trier Social Stress Test) or a control version while blood, saliva, heart rate, and psychometrics were sampled. T1-weighted MP2RAGE images at 3T MRI were acquired 45 min before and 90 min after intervention onset. GMV changes were analysed using voxel-based morphometry. Associations with endocrine, autonomic, and subjective stress measures were tested with linear models. We found significant group-by-time interactions in several brain clusters including anterior/mid-cingulate cortices and bilateral insula: GMV was increased in the stress group relative to the control group, in which several clusters showed a GMV decrease. We found no significant group-by-time interaction for other MRI parameters, including cerebral blood flow, but a significant association of GMV changes with state anxiety and heart rate variability changes. In summary, we show rapid GMV changes following acute psychosocial stress in humans. The results suggest that endogenous circadian brain changes are counteracted by acute stress and generally emphasize the influence of stress on the brain.