Peripheral inflammation is associated with micro-structural and functional connectivity changes in depression-related brain networks

作者：Manfred G. Kitzbichler, Athina R. Aruldass, Gareth J. Barker, Tobias Wood, Nicholas G. Dowell, Samuel A. Hurley, John McLean, Marta Correia, Charlotte Clarke, Linda Pointon, Jonathan Cavanagh, Philip J. Cowen, Carmine M. Pariante, Mara Cercignani, Edward T. Bullmore, Neil A. Harrison · 发表于：medRxiv · 年份：2020 · DOI：10.1101/2020.09.09.20191262 · 被引用次数：11 · 研究领域：Tryptophan and brain disorders、Functional Brain Connectivity Studies、Stress Responses and Cortisol

Abstract Peripheral inflammation can cause depressive symptoms – but how? Here, we measured brain MRI functional connectivity and micro-structural parameters, including proton density (PD, a measure of tissue water), at 360 cortical and 16 subcortical brain regions in 46 healthy controls and 83 depressed cases. Blood C-reactive protein (CRP) was positively correlated with PD in key precuneus/posterior cingulate cortex (pC/pCC) and medial prefrontal cortex (mPFC) components of the default mode network (DMN). CRP concentration was associated with increased connectivity within the DMN (nodes pC/pCC, mPFC and hippocampus), but decreased connectivity between DMN and non-DMN nodes. Depressed cases had reduced weighted degree, a metric of hubness, in anatomically co-located DMN regions. Our interpretation is that low-grade peripheral inflammation is associated with increased water (oedema) within a few highly connected but metabolically vulnerable medial cortical nodes, and this “rock in the pond” serves to perturb the functional connectivity of large-scale cortico-subcortical systems associated with depression.