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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

Behavioral significance of the bilateral hippocampal functional connectivity networks across all subjects (p < 0.05, AlphaSim correction). Top row: Main effects of the depressive symptoms on the bilateral HFC networks; Middle row: Main effects of the episodic memory scores (LMIIDR scores) on the bilateral HFC networks. Bright color indicates positive correlation and blue color indicates negative correlation; Bottom row: Interaction of depressive symptoms and memory function on the bilateral HFC networks. Bright color indicates that the interactive effects are positively correlated with bilateral HFC; blue color demonstrates that the interactive effects are negatively correlated with bilateral HFC. Color bar is presented with z scores.Abbreviations: GDS, geriatric depression scale; LHFC, left hippocampal functional connectivity; RHFC, right hippocampal functional connectivity; LDLPFC, left dorsolateral prefrontal cortex; RDLPFC, right dorsolateral prefrontal cortex; LDMPFC, left dorsomedial prefrontal cortex; RDMPFC, right dorsomedial prefrontal cortex; LITC, left inferior temporal cortex; RITC, right inferior temporal cortex; LHip/PHG, left hippocampus/parahippocampal gyrus; RHip/PHG, right hippocampus/parahippocampal gyrus; LIPC, left inferior parietal cortex; RIPC, right inferior parietal cortex; LaI/fO, left anterior insula/frontal operculum; RaI/fO, right anterior insula/frontal operculum; LIFG, left inferior frontal gyrus; LTha, left thalamus; L Pcu/PCG, precuneus/postcentral gyrus; Pcu/PCG, precuneus/postcentral gyrus; vmPFC, ventromedial prefrontal cortex; Amy/PHG, amygdala/parahippocampal gyrus; RpMTG, right posterior middle temporal gyrus. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
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f0020: Behavioral significance of the bilateral hippocampal functional connectivity networks across all subjects (p < 0.05, AlphaSim correction). Top row: Main effects of the depressive symptoms on the bilateral HFC networks; Middle row: Main effects of the episodic memory scores (LMIIDR scores) on the bilateral HFC networks. Bright color indicates positive correlation and blue color indicates negative correlation; Bottom row: Interaction of depressive symptoms and memory function on the bilateral HFC networks. Bright color indicates that the interactive effects are positively correlated with bilateral HFC; blue color demonstrates that the interactive effects are negatively correlated with bilateral HFC. Color bar is presented with z scores.Abbreviations: GDS, geriatric depression scale; LHFC, left hippocampal functional connectivity; RHFC, right hippocampal functional connectivity; LDLPFC, left dorsolateral prefrontal cortex; RDLPFC, right dorsolateral prefrontal cortex; LDMPFC, left dorsomedial prefrontal cortex; RDMPFC, right dorsomedial prefrontal cortex; LITC, left inferior temporal cortex; RITC, right inferior temporal cortex; LHip/PHG, left hippocampus/parahippocampal gyrus; RHip/PHG, right hippocampus/parahippocampal gyrus; LIPC, left inferior parietal cortex; RIPC, right inferior parietal cortex; LaI/fO, left anterior insula/frontal operculum; RaI/fO, right anterior insula/frontal operculum; LIFG, left inferior frontal gyrus; LTha, left thalamus; L Pcu/PCG, precuneus/postcentral gyrus; Pcu/PCG, precuneus/postcentral gyrus; vmPFC, ventromedial prefrontal cortex; Amy/PHG, amygdala/parahippocampal gyrus; RpMTG, right posterior middle temporal gyrus. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Mentions: The GDS scores positively correlated with the left HFC network in the DMPFC and inferior temporal cortex (ITC) bilaterally; negatively correlated with the left HFC network in the hippocampus/PHG bilaterally, and left DLPFC. The GDS scores positively correlated with the right HFC in the bilateral DMPFC and ITC, right pMTG, and negatively correlated in the bilateral DLPFC, vmPFC, and hippocampus/PHG, left IFG, and right IPC and anterior insula/frontal operculum (aI/fO) (Fig. 4 top row).


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)

Behavioral significance of the bilateral hippocampal functional connectivity networks across all subjects (p < 0.05, AlphaSim correction). Top row: Main effects of the depressive symptoms on the bilateral HFC networks; Middle row: Main effects of the episodic memory scores (LMIIDR scores) on the bilateral HFC networks. Bright color indicates positive correlation and blue color indicates negative correlation; Bottom row: Interaction of depressive symptoms and memory function on the bilateral HFC networks. Bright color indicates that the interactive effects are positively correlated with bilateral HFC; blue color demonstrates that the interactive effects are negatively correlated with bilateral HFC. Color bar is presented with z scores.Abbreviations: GDS, geriatric depression scale; LHFC, left hippocampal functional connectivity; RHFC, right hippocampal functional connectivity; LDLPFC, left dorsolateral prefrontal cortex; RDLPFC, right dorsolateral prefrontal cortex; LDMPFC, left dorsomedial prefrontal cortex; RDMPFC, right dorsomedial prefrontal cortex; LITC, left inferior temporal cortex; RITC, right inferior temporal cortex; LHip/PHG, left hippocampus/parahippocampal gyrus; RHip/PHG, right hippocampus/parahippocampal gyrus; LIPC, left inferior parietal cortex; RIPC, right inferior parietal cortex; LaI/fO, left anterior insula/frontal operculum; RaI/fO, right anterior insula/frontal operculum; LIFG, left inferior frontal gyrus; LTha, left thalamus; L Pcu/PCG, precuneus/postcentral gyrus; Pcu/PCG, precuneus/postcentral gyrus; vmPFC, ventromedial prefrontal cortex; Amy/PHG, amygdala/parahippocampal gyrus; RpMTG, right posterior middle temporal gyrus. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f0020: Behavioral significance of the bilateral hippocampal functional connectivity networks across all subjects (p < 0.05, AlphaSim correction). Top row: Main effects of the depressive symptoms on the bilateral HFC networks; Middle row: Main effects of the episodic memory scores (LMIIDR scores) on the bilateral HFC networks. Bright color indicates positive correlation and blue color indicates negative correlation; Bottom row: Interaction of depressive symptoms and memory function on the bilateral HFC networks. Bright color indicates that the interactive effects are positively correlated with bilateral HFC; blue color demonstrates that the interactive effects are negatively correlated with bilateral HFC. Color bar is presented with z scores.Abbreviations: GDS, geriatric depression scale; LHFC, left hippocampal functional connectivity; RHFC, right hippocampal functional connectivity; LDLPFC, left dorsolateral prefrontal cortex; RDLPFC, right dorsolateral prefrontal cortex; LDMPFC, left dorsomedial prefrontal cortex; RDMPFC, right dorsomedial prefrontal cortex; LITC, left inferior temporal cortex; RITC, right inferior temporal cortex; LHip/PHG, left hippocampus/parahippocampal gyrus; RHip/PHG, right hippocampus/parahippocampal gyrus; LIPC, left inferior parietal cortex; RIPC, right inferior parietal cortex; LaI/fO, left anterior insula/frontal operculum; RaI/fO, right anterior insula/frontal operculum; LIFG, left inferior frontal gyrus; LTha, left thalamus; L Pcu/PCG, precuneus/postcentral gyrus; Pcu/PCG, precuneus/postcentral gyrus; vmPFC, ventromedial prefrontal cortex; Amy/PHG, amygdala/parahippocampal gyrus; RpMTG, right posterior middle temporal gyrus. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
Mentions: The GDS scores positively correlated with the left HFC network in the DMPFC and inferior temporal cortex (ITC) bilaterally; negatively correlated with the left HFC network in the hippocampus/PHG bilaterally, and left DLPFC. The GDS scores positively correlated with the right HFC in the bilateral DMPFC and ITC, right pMTG, and negatively correlated in the bilateral DLPFC, vmPFC, and hippocampus/PHG, left IFG, and right IPC and anterior insula/frontal operculum (aI/fO) (Fig. 4 top row).

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