title: The Rich-Club Organization in Rat Functional Brain Network to Balance Between Communication Cost and Efficiency.
abstract: Network analyses of structural connectivity in the brain have highlighted a set of highly connected hubs that are densely interconnected, forming a "rich-club" substrate in diverse species. Here, we demonstrate the existence of rich-club organization in functional brain networks of rats. Densely interconnected rich-club regions are found to be distributed in multiple brain modules, with the majority located within the putative default mode network. Rich-club members exhibit high wiring cost (as measured by connection distance) and high metabolic running cost (as surrogated by cerebral blood flow), which may have evolved to achieve high network communications to support efficient brain functions. Furthermore, by adopting a forepaw electrical stimulation paradigm, we find that the rich-club organization of the rat functional network remains almost the same as in the resting state, whereas path motif analysis reveals significant differences, suggesting the rat brain reorganizes its topological routes by increasing locally oriented shortcuts but reducing rich-club member-involved paths to conserve metabolic running cost during unimodal stimulation. Together, our results suggest that the neuronal system is organized and dynamically operated in an economic way to balance between cost minimization and topological/functional efficiency.
authors.affiliation: Neuroimaging Research Branch, National Institute on Drug Abuse, Baltimore, MD 21224, USA.|Research Center of Basic Space Science, Harbin Institute of Technology, Harbin 150001, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Liang
authors.affiliation: Neuroimaging Research Branch, National Institute on Drug Abuse, Baltimore, MD 21224, USA.|Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 11221, Taiwan.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Hsu
authors.affiliation: Neuroimaging Research Branch, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
authors.forename: Hanbing
authors.initials: H
authors.lastname: Lu
authors.affiliation: Neuroimaging Research Branch, National Institute on Drug Abuse, Baltimore, MD 21224, USA.|Institute of Development, Aging and Cancer, Tohoku University, Sendai 9808575, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sumiyoshi
authors.affiliation: State Key Laboratory of Cognitive Neuroscience and Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: He
authors.affiliation: Neuroimaging Research Branch, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
authors.forename: Yihong
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D063132:Connectome / Q000379:methods*; D004558:Electric Stimulation; D005552:Forelimb / Q000294:innervation; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000502:physiology*; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010100:Oxygen
keywords: functional connectome; module; motif; rat brain; rich club