title: Reorganization of brain connectivity in obesity.
abstract: Global brain connectivity (GBC) identifies regions of the brain, termed "hubs," which are densely connected and metabolically costly, and have a wide influence on brain function. Since obesity is associated with central and peripheral metabolic dysfunction we sought to determine if GBC is altered in obesity. Two independent fMRI data sets were subjected to GBC analyses. The first data set was acquired while participants (n = 15 healthy weight and 15 obese) tasted milkshake and the second with participants at rest (n = 33 healthy weight and 28 obese). In the resting state and during milkshake consumption GBC is consistently decreased in the ventromedial and ventrolateral prefrontal cortex, insula and caudate nucleus, and increased in brain regions belonging to the dorsal attention network including premotor areas, superior parietal lobule, and visual cortex. During milkshake consumption, but not at rest, additional decreases in GBC are observed in feeding-related circuitry including the insula, amygdala, anterior hippocampus, hypothalamus, midbrain, brainstem and somatomotor cortex. Additionally, GBC differences were not accounted for by age. These results demonstrate that obesity is associated with decreased GBC in prefrontal and feeding circuits and increased GBC in the dorsal attention network. We therefore conclude that global brain organization is altered in obesity to favor networks important for external orientation over those monitoring homeostatic state and guiding feeding decisions. Furthermore, since prefrontal decreases are also observed at rest in obese individuals future work should evaluate whether these changes are associated with neurocognitive impairments frequently observed in obesity and diabetes. Hum Brain Mapp 38:1403-1420, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.|The John B. Pierce Laboratory, New Haven, Connecticut.
authors.forename: Paul
authors.initials: P
authors.lastname: Geha
authors.affiliation: Thomas J. Watson Research Center, Yorktown Heights, New York.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Cecchi
authors.affiliation: Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: R
authors.initials: R
authors.lastname: Todd Constable
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: Chadi
authors.initials: C
authors.lastname: Abdallah
authors.affiliation: Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.|The John B. Pierce Laboratory, New Haven, Connecticut.|Department of Psychology, Yale University, New Haven, Connecticut.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Small
mesh_terms: D000328:Adult; D000367:Age Factors; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001931:Brain Mapping; D004435:Eating; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009038:Motion; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology*; D009765:Obesity / Q000000981:diagnostic imaging / Q000473:pathology*; D010100:Oxygen / Q000097:blood
chemical_list: D010100:Oxygen
keywords: attention; connectivity; feeding; internal milieu; obesity; resting state; reward