Title
Abnormal insula functional network is associated with episodic memory decline in amnestic mild cognitive impairment.
Abstract
Abnormalities of functional connectivity in the default mode network (DMN) recently have been reported in patients with amnestic mild cognitive impairment (aMCI), Alzheimer's disease (AD) or other psychiatric diseases. As such, these abnormalities may be epiphenomena instead of playing a causal role in AD progression. To date, few studies have investigated specific brain networks, which extend beyond the DMN involved in the early AD stages, especially in aMCI. The insula is one site affected by early pathological changes in AD and is a crucial hub of the human brain networks. Currently, we explored the contribution of the insula networks to cognitive performance in aMCI patients. Thirty aMCI and 26 cognitively normal (CN) subjects participated in this study. Intrinsic connectivity of the insula networks was measured, using the resting-state functional connectivity fMRI approach. We examined the differential connectivity of insula networks between groups, and the neural correlation between the altered insula networks connectivity and the cognitive performance in aMCI patients and CN subjects, respectively. Insula subregional volumes were also investigated. AMCI subjects, when compared to CN subjects, showed significantly reduced right posterior insula volumes, cognitive deficits and disrupted intrinsic connectivity of the insula networks. Specifically, decreased intrinsic connectivity was primarily located in the frontal–parietal network and the cingulo-opercular network, including the anterior prefrontal cortex (aPFC), anterior cingulate cortex, operculum, inferior parietal cortex and precuneus. Increased intrinsic connectivity was primarily situated in the visual–auditory pathway, which included the posterior superior temporal gyrus and middle occipital gyrus. Conjunction analysis was performed; and significantly decreased intrinsic connectivity in the overlapping regions of the anterior and posterior insula networks, including the bilateral aPFC, left dorsolateral prefrontal cortex, dorsomedial prefrontal cortex, and anterior temporal pole was found. Furthermore, the disrupted intrinsic connectivity was associated with episodic memory (EM) deficits in the aMCI patients and not in the CN subjects. These findings demonstrated that the functional integration of the insula networks plays an important role in the EM process. They provided new insight into the neural mechanism underlying the memory deficits in aMCI patients.
Year
DOI
Venue
2012
10.1016/j.neuroimage.2012.06.062
NeuroImage
Keywords
Field
DocType
Insula network,Episodic memory,Cognition,Amnestic mild cognitive impairment,Functional connectivity fMRI
Insula,Developmental psychology,Episodic memory,Default mode network,Precuneus,Neuroscience,Prefrontal cortex,Psychology,Cognitive psychology,Posterior parietal cortex,Anterior cingulate cortex,Effects of sleep deprivation on cognitive performance
Journal
Volume
Issue
ISSN
63
1
1053-8119
Citations 
PageRank 
References 
5
0.48
6
Authors
10
Name
Order
Citations
PageRank
Chunming Xie1272.88
Feng Bai250.48
Hui Yu350.48
Yongmei Shi49811.59
Yonggui Yuan562.12
Gang Chen6272.21
Wenjun Li750.48
Guangyu Chen8272.73
Zhijun Zhang950.48
Shi-Jiang Li10406.21