White matter changes in microstructure associated with a maladaptive response to stress in rats
R Magalhães1,2,3, J Bourgin1,4,5, F Boumezbeur6
1Physiopathologie des Maladies Psychiatriques, UMR_S 894 Inserm, Centre de Psychiatrie et Neurosciences, Paris, France.
Translational Psychiatry
|January 25, 2017
Summary
This study used diffusion MRI to investigate stress responses in two rat strains. Sprague-Dawley rats showed brain white matter changes, suggesting adaptation to stress through plasticity.
Area of Science:
- Neuroscience
- Stress Research
- Neuroimaging
Background:
- Stress exposure significantly impacts mental health and quality of life.
- Individual responses to stress vary due to differing adaptation mechanisms.
- Understanding neural adaptations to stress is crucial for developing interventions.
Purpose of the Study:
- To compare white matter properties between Fisher 344 (F344) and Sprague-Dawley (SD) rats under stress.
- To investigate the effects of a repeated inescapable stress paradigm on rat brain white matter.
- To identify neural specificities underlying differential stress adaptation.
Main Methods:
- Ex vivo high-field diffusion magnetic resonance imaging (dMRI) was employed.
- Tract-based spatial statistics (TBSS) analysis was applied to 25 rat brains.
- Repeated inescapable stress paradigm was administered for two weeks.
Main Results:
- Stressed SD rats exhibited lower corticosterone levels than F344 rats.
- Stress increased fractional anisotropy (FA) and reduced mean and radial diffusivity (MD, RD) in white matter.
- SD rats showed strain-by-stress interactions with reduced MD, RD, and axial diffusivity (AD) in specific brain regions.
Conclusions:
- SD rats may adapt to stress via synaptic and structural plasticity, potentially involving learning processes.
- dMRI reveals distinct white matter alterations in response to stress in different rat strains.
- Findings highlight the role of white matter plasticity in stress adaptation and resilience.
