Faculty Collaboration Database

Late-life depression, mild cognitive impairment and hippocampal functional network architecture. Neuroimage Clin 2013;3:311-20

Date

11/26/2013

Pubmed ID

24273715

Pubmed Central ID

PMC3814948

DOI

10.1016/j.nicl.2013.09.002

Scopus ID

2-s2.0-84885143973 (requires institutional sign-in at Scopus site)   24 Citations

Abstract

Late-life depression (LLD) and amnestic mild cognitive impairment (aMCI) are associated with medial temporal lobe structural abnormalities. However, the hippocampal functional connectivity (HFC) similarities and differences related to these syndromes when they occur alone or coexist are unclear. Resting-state functional connectivity MRI (R-fMRI) technique was used to measure left and right HFC in 72 elderly participants (LLD [n = 18], aMCI [n = 17], LLD with comorbid aMCI [n = 12], and healthy controls [n = 25]). The main and interactive relationships of LLD and aMCI on the HFC networks were determined, after controlling for age, gender, education and gray matter volumes. The effects of depressive symptoms and episodic memory deficits on the hippocampal functional connections also were assessed. While increased and decreased left and right HFC with several cortical and subcortical structures involved in mood regulation were related to LLD, aMCI was associated with globally diminished connectivity. Significant LLD-aMCI interactions on the right HFC networks were seen in the brain regions critical for emotion processing and higher-order cognitive functions. In the interactive brain regions, LLD and aMCI were associated with diminished hippocampal functional connections, whereas the comorbid group demonstrated enhanced connectivity. Main and interactive effects of depressive symptoms and episodic memory performance were also associated with bilateral HFC network abnormalities. In conclusion, these findings indicate that discrete hippocampal functional network abnormalities are associated with LLD and aMCI when they occur alone. However, when these conditions coexist, more pronounced vulnerabilities of the hippocampal networks occur, which may be a marker of disease severity and impending cognitive decline. By utilizing R-fMRI technique, this study provides novel insights into the neural mechanisms underlying LLD and aMCI in the functional network level.

Author List

Xie C, Li W, Chen G, Ward BD, Franczak MB, Jones JL, Antuono PG, Li SJ, Goveas JS

Authors

Piero G. Antuono MD Professor in the Neurology department at Medical College of Wisconsin
Malgorzata Franczak MD Professor in the Neurology department at Medical College of Wisconsin
Joseph S. Goveas MD Professor in the Psychiatry and Behavioral Medicine department at Medical College of Wisconsin