title: Unravelling the intrinsic functional organization of the human striatum: a parcellation and connectivity study based on resting-state FMRI.
abstract: As the main input hub of the basal ganglia, the striatum receives projections from the cerebral cortex. Many studies have provided evidence for multiple parallel corticostriatal loops based on the structural and functional connectivity profiles of the human striatum. A recent resting-state fMRI study revealed the topography of striatum by assigning each voxel in the striatum to its most strongly correlated cortical network among the cognitive, affective, and motor networks. However, it remains unclear what patterns of striatal parcellation would result from performing the clustering without subsequent assignment to cortical networks. Thus, we applied unsupervised clustering algorithms to parcellate the human striatum based on its functional connectivity patterns to other brain regions without any anatomically or functionally defined cortical targets. Functional connectivity maps of striatal subdivisions, identified through clustering analyses, were also computed. Our findings were consistent with recent accounts of the functional distinctions of the striatum as well as with recent studies about its functional and anatomical connectivity. For example, we found functional connections between dorsal and ventral striatal clusters and the areas involved in cognitive and affective processes, respectively, and between rostral and caudal putamen clusters and the areas involved in cognitive and motor processes, respectively. This study confirms prior findings, showing similar striatal parcellation patterns between the present and prior studies. Given such striking similarity, it is suggested that striatal subregions are functionally linked to cortical networks involving specific functions rather than discrete portions of cortical regions. Our findings also demonstrate that the clustering of functional connectivity patterns is a reliable feature in parcellating the striatum into anatomically and functionally meaningful subdivisions. The striatal subdivisions identified here may have important implications for understanding the relationship between corticostriatal dysfunction and various neurodegenerative and psychiatric disorders.
authors.affiliation: Institute of Human Behavioral Medicine, Seoul National University-Medical Research Center, Seoul, South Korea.
authors.forename: Wi Hoon
authors.initials: WH
authors.lastname: Jung
authors.affiliation: Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Joon Hwan
authors.initials: JH
authors.lastname: Jang
authors.affiliation: Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Park
authors.affiliation: Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Euitae
authors.initials: E
authors.lastname: Kim
authors.affiliation: Department of Radiological Science, Cheong-ju University, Cheongju, South Korea.
authors.forename: Eun-Hoe
authors.initials: EH
authors.lastname: Goo
authors.affiliation: Department of Diagnostic Radiology, Seoul National University Hospital, Seoul, South Korea.
authors.forename: Oh-Soo
authors.initials: OS
authors.lastname: Im
authors.affiliation: Institute of Human Behavioral Medicine, Seoul National University-Medical Research Center, Seoul, South Korea; Department of Psychiatry, Seoul National University College of Medicine, Seoul, South Korea; Deparment of Brain & Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea.
authors.forename: Jun Soo
authors.initials: JS
authors.lastname: Kwon
mesh_terms: D000328:Adult; D000465:Algorithms; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D017072:Neostriatum / Q000166:cytology*; D009415:Nerve Net / Q000166:cytology*; D012146:Rest