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Late-life depression, mild cognitive impairment and hippocampal functional network architecture.

Xie C, Li W, Chen G, Ward BD, Franczak MB, Jones JL, Antuono PG, Li SJ, Goveas JS - Neuroimage Clin (2013)

Bottom Line: 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.In the interactive brain regions, LLD and aMCI were associated with diminished hippocampal functional connections, whereas the comorbid group demonstrated enhanced connectivity.By utilizing R-fMRI technique, this study provides novel insights into the neural mechanisms underlying LLD and aMCI in the functional network level.

View Article: PubMed Central - PubMed

Affiliation: Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA.

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.

No MeSH data available.


Related in: MedlinePlus

Whole-brain voxelwise pattern of the left hippocampal functional connectivity (LHFC) networks in the four group subjects (p < 0.01, AlphaSim correction). Bright color indicates positive connectivity and blue color indicates negative or anticorrelated connectivity. Color bar is presented with z scores. Abbreviation: CN, control; Dep, depression; aMCI, amnestic mild cognitive impairment; dMCI, depressed mild cognitive impairment.
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f0025: Whole-brain voxelwise pattern of the left hippocampal functional connectivity (LHFC) networks in the four group subjects (p < 0.01, AlphaSim correction). Bright color indicates positive connectivity and blue color indicates negative or anticorrelated connectivity. Color bar is presented with z scores. Abbreviation: CN, control; Dep, depression; aMCI, amnestic mild cognitive impairment; dMCI, depressed mild cognitive impairment.


Late-life depression, mild cognitive impairment and hippocampal functional network architecture.

Xie C, Li W, Chen G, Ward BD, Franczak MB, Jones JL, Antuono PG, Li SJ, Goveas JS - Neuroimage Clin (2013)

Whole-brain voxelwise pattern of the left hippocampal functional connectivity (LHFC) networks in the four group subjects (p < 0.01, AlphaSim correction). Bright color indicates positive connectivity and blue color indicates negative or anticorrelated connectivity. Color bar is presented with z scores. Abbreviation: CN, control; Dep, depression; aMCI, amnestic mild cognitive impairment; dMCI, depressed mild cognitive impairment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3814948&req=5

f0025: Whole-brain voxelwise pattern of the left hippocampal functional connectivity (LHFC) networks in the four group subjects (p < 0.01, AlphaSim correction). Bright color indicates positive connectivity and blue color indicates negative or anticorrelated connectivity. Color bar is presented with z scores. Abbreviation: CN, control; Dep, depression; aMCI, amnestic mild cognitive impairment; dMCI, depressed mild cognitive impairment.
Bottom Line: 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.In the interactive brain regions, LLD and aMCI were associated with diminished hippocampal functional connections, whereas the comorbid group demonstrated enhanced connectivity.By utilizing R-fMRI technique, this study provides novel insights into the neural mechanisms underlying LLD and aMCI in the functional network level.

View Article: PubMed Central - PubMed

Affiliation: Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA.

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.

No MeSH data available.


Related in: MedlinePlus