Shifting priorities: highly conserved behavioral and brain network adaptations to chronic stress across species
Translational Psychiatry, January 2018
Authors: Yuliya S. Nikolova, Keith A. Misquitta, Brad R. Rocco, Thomas D. Prevot, Annchen R. Knodt, Jacob Ellegood, Aristotle N. Voineskos, Jason P. Lerch, Ahmad R. Hariri, Etienne Sibille & Mounira Banasr
Abstract
Parallel clinical and preclinical research have begun to illuminate the biological basis of stress-related disorders, including major depression, but translational bridges informing discrete mechanistic targets for intervention are missing. To address this critical need, we used structural MRI in a mouse model and in a large human sample to examine stress effects on brain structure that may be conserved across species. Specifically, we focused on a previously unexplored approach, whole-brain structural covariance, as it reflects synchronized changes in neuroanatomy, potentially due to mutual trophic influences or shared plasticity across regions. Using the unpredictable chronic mild stress (UCMS) paradigm in mouse we first demonstrate that UCMS-induced elevated behavioral emotionality correlates with increased size of the amygdala and other corticolimbic regions. We further identify focal increases in the amygdala’s ‘hubness’ (degree and strength) set against the background of a global stress-related loss of network clustering and modularity.