Desynchronization and Plasticity of Striato-frontal Connectivity in Major Depressive Disorder

Amber M Leaver; Randall Espinoza; Shantanu H Joshi; Megha Vasavada; Stephanie Njau; Roger P Woods; Katherine L Narr

doi:10.1093/cercor/bhv207

Desynchronization and Plasticity of Striato-frontal Connectivity in Major Depressive Disorder

Cereb Cortex. 2016 Oct 17;26(11):4337-4346. doi: 10.1093/cercor/bhv207. Epub 2015 Sep 22.

Authors

Amber M Leaver¹, Randall Espinoza², Shantanu H Joshi¹, Megha Vasavada¹, Stephanie Njau¹, Roger P Woods³, Katherine L Narr³

Affiliations

¹ Ahmanson-Lovelace Brain Mapping Center, Department of Neurology.
² Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA 90095, USA.
³ Ahmanson-Lovelace Brain Mapping Center, Department of Neurology Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA 90095, USA.

Abstract

Major depressive disorder (MDD) is associated with dysfunctional corticolimbic networks, making functional connectivity studies integral for understanding the mechanisms underlying MDD pathophysiology and treatment. Resting-state functional connectivity (RSFC) studies analyze patterns of temporally coherent intrinsic brain activity in "resting-state networks" (RSNs). The default-mode network (DMN) has been of particular interest to depression research; however, a single RSN is unlikely to capture MDD pathophysiology in its entirety, and the DMN itself can be characterized by multiple RSNs. This, coupled with conflicting previous results, underscores the need for further research. Here, we measured RSFC in MDD by targeting RSNs overlapping with corticolimbic regions and further determined whether altered patterns of RSFC were restored with electroconvulsive therapy (ECT). MDD patients exhibited hyperconnectivity between ventral striatum (VS) and the ventral default-mode network (vDMN), while simultaneously demonstrating hypoconnectivity with the anterior DMN (aDMN). ECT influenced this pattern: VS-vDMN hyperconnectivity was significantly reduced while VS-aDMN hypoconnectivity only modestly improved. RSFC between the salience RSN and dorsomedial prefrontal cortex was also reduced in MDD, but was not affected by ECT. Taken together, our results support a model of ventral/dorsal imbalance in MDD and further suggest that the VS is a key structure contributing to this desynchronization.

Keywords: connectivity; default-mode network; depression; limbic; ventral striatum.

Abstract

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