Anesthesiology
September 30, 2010
Pierre Boveroux, Audrey Vanhaudenhuyse, Marie‐Aurélie Bruno et al.
645 citations
Propofol-induced unconsciousness is linked to decreased connectivity within frontoparietal networks (the default-mode and executive-control networks) and between the thalamus and these networks, with a negative correlation between thalamic and cortical activity emerging during unconsciousness. In contrast, connectivity in low-level sensory cortices (auditory and visual networks) is preserved, including their thalamocortical connections. Loss of consciousness is associated with a breakdown of cross-modal interactions between visual and auditory networks. These findings suggest that unconsciousness results from disrupted communication between sensory and higher-order frontoparietal cortices, preventing conscious perception.
NeuroImage
April 11, 2010
Kaustubh Supekar, Lucina Q. Uddin, Katherine E. Prater et al.
548 citations
The default-mode network (DMN) undergoes significant developmental changes in functional and structural connectivity from childhood to adulthood, but these changes are not uniform across all DMN nodes. The connection between the posterior cingulate cortex (PCC) and medial prefrontal cortex (mPFC) along the cingulum bundle is the most immature link in children. Structural connectivity between PCC and left medial temporal lobe is weak or non-existent in children, yet functional connectivity does not differ from adults. Gray matter volume differences and macrostructural and microstructural differences in the dorsal cingulum bundle also appear. Maturation of PCC-mPFC structural connectivity likely supports self-related and social-cognitive functions emerging during adolescence.
Cerebral Cortex
March 7, 2011
Elizabeth C. Mormino, Andre Smiljic, Amynta O. Hayenga et al.
349 citations
Beta-amyloid deposition, a hallmark of Alzheimer's disease, is also common in cognitively normal older adults. Using Pittsburgh compound-B PET imaging, the study found that greater beta-amyloid burden in normal controls is associated with altered functional connectivity within the default mode network during rest. Connectivity decreased in regions critical for episodic memory, including posteromedial cortex, ventral medial prefrontal cortex, and angular gyrus, while increases appeared in dorsal and anterior medial prefrontal and lateral temporal cortices. The decreases align with known vulnerability of memory-related areas in Alzheimer's disease, and the increases may reflect compensatory mechanisms.