A winding road: Alzheimer’s disease increases circuitous functional connectivity pathways

Frontiers in Computational Neuroscience

John eO'Brien¹  Roger eTait²  John eSuckling²  Shayanti eChattopadhyay³  James eRowe³  Tiago eSimas³  Li eSu³  Guy eWilliams⁴ 

[1] Cambridge and Peterborough Foundation NHS Trust;MRC/Wellcome Trust Behavioural and Clinical Neuroscience Institute, University of Cambridge;University of Cambridge;Wolfson Brain Imaging Centre, University of Cambridge;

关键词: Alzheimer Disease;    Neuroimaging;    functional connectivity;    connectome;    Transitivity;    semi metricity;   

DOI  :  10.3389/fncom.2015.00140

来源: DOAJ

【 摘 要 】

Neuroimaging has been successful in characterising the pattern of cerebral atrophy that accompanies the progression of Alzheimer’s disease (AD). Examination of functional connectivity, the strength of signal synchronicity between brain regions, has gathered pace as another way of understanding changes to the brain that are associated with AD. It appears to have good sensitivity and detect effects that precede cognitive decline, and thus offers the possibility to understand the neurobiology of the disease in its earliest phases. However, functional connectivity analyses to date generally consider only the strongest connections, with weaker links ignored. This proof-of-concept study compared patients with mild-to-moderate AD (N=11) and matched control individuals (N=12) based on functional connectivities derived from blood-oxygenation level dependent (BOLD) sensitive functional MRI acquired during resting wakefulness. All positive connectivities irrespective of their strength were included. Transitive closures of the resulting connectome were calculated that classified connections as either direct or indirect. Between-group differences in the proportion of indirect paths were observed. In AD, there was broadly increased indirect connectivity across greater spatial distances. Furthermore, the indirect pathways in AD had greater between-subject topological variance than controls.The prevailing characterisation of AD as being a disconnection syndrome is refined by the observation that direct links between regions that are impaired are perhaps replaced by an increase in indirect functional pathways that is only detectable through inclusion of connections across the entire range of connection strengths.

【 授权许可】

Unknown