Alterations of functional connectivity and intrinsic activity within the cingulate cortex of suicidal ideators

• Published in: Journal of affective disorders Vol. 212; pp. 78 - 85
• Main Authors: Chase, Henry W, Segreti, Anna Maria, Keller, Tim, Cherkassky, Vlad, Just, Marcel, Pan, Lisa, Brent, David
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-04-2017
• Subjects: Adult; Brain Mapping; Default mode network; Diffusion Tensor Imaging; Emotions; Female; Functional connectivity; Gyrus Cinguli - anatomy & histology; Gyrus Cinguli - diagnostic imaging; Gyrus Cinguli - physiology; Humans; Low frequency oscillations; Magnetic Resonance Imaging; Male; Neural Pathways - anatomy & histology; Neural Pathways - diagnostic imaging; Psychiatry; Resting state fMRI; Suicidal Ideation; Young Adult; Functional connectivity; Resting state fMRI; Default mode network; Low frequency oscillations; Suicidal ideation; Diffusion tensor imaging
• ISSN: 0165-0327; 1573-2517
• DOI: 10.1016/j.jad.2017.01.013

Abstract The ‘default mode network’ (DMN), a collection of brain regions including the posterior cingulate cortex (PCC), shows reliable inter-regional functional connectivity at rest. It has been implicated in rumination and other negative affective states, but its role in suicidal ideation is not well understood. We employed seed based functional connectivity methods to analyze resting state fMRI data in 34 suicidal ideators and 40 healthy control participants. Whole-brain connectivity with dorsal PCC or ventral PCC was broadly intact between the two groups, but while the control participants showed greater coupling between the dorsal anterior cingulate cortex (dACC) and dorsal PCC, compared to the dACC and ventral PCC, this difference was reversed in the ideators. Furthermore, ongoing low frequency BOLD signal in these three regions (dorsal, ventral PCC, dACC) was reduced in the ideators. The structural integrity of the cingulum bundle, as measured using diffusion tensor imaging (DTI), also explained variation in the functional connectivity measures but did not abolish the group differences. Together, these findings provide evidence of abnormalities in the DMN underlying the tendency towards suicidal ideation.