title: Decreased functional connectivity of the amygdala in Alzheimer's disease revealed by resting-state fMRI.
abstract: Alzheimer's disease (AD), the most common cause of dementia, is thought to be a progressive neurodegenerative disease that is clinically characterised by a decline of memory and other cognitive functions. Mild cognitive impairment (MCI) is considered to be the prodromal stage of AD. However, the relationship between AD and MCI and the development process remains unclear. The amygdala is one of the most vulnerable structures in the early stages of AD. To our knowledge, this is the first report on the alteration of the functional connectivity of the amygdala in AD and MCI subjects. We hypothesised that the amygdala-cortical loop is impaired in AD and that these alterations relate to the disease severity. In our study, we used resting-state functional MRIs to investigate the altered amygdala connectivity patterns in 35 AD patients, 27 MCI patients and 27 age- and gender-matched normal controls (NC). Compared with the NC, the decreased functional connectivity found in the AD patients was mainly located between the amygdala and the regions that are included in the default mode, context conditioning and extinction networks. Importantly, the decreased functional connectivity between the amygdala and some of the identified regions was positively correlated with MMSE, which indicated that the cognitive function impairment is related to an altered functional connectivity pattern.
authors: Department of Radiology, Chinese PLA General Hospital, Beijing 100853, China.
authors: Hongxiang
authors: H
authors: Yao
authors: Yong
authors: Y
authors: Liu
authors: Bo
authors: B
authors: Zhou
authors: Zengqiang
authors: Z
authors: Zhang
authors: Ningyu
authors: N
authors: An
authors: Pan
authors: P
authors: Wang
authors: Luning
authors: L
authors: Wang
authors: Xi
authors: X
authors: Zhang
authors: Tianzi
authors: T
authors: Jiang
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D000679:Amygdala / Q000503:physiopathology*; D001931:Brain Mapping; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D063132:Connectome / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology*; D009434:Neural Pathways / Q000503:physiopathology; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity
keywords: Alzheimer's disease; Amygdala; Mild cognitive impairment; Resting-state fMRI