title: Functional network of the basal ganglia and cerebellar motor loops in vivo: different activation patterns between self-initiated and externally triggered movements.
abstract: The basal ganglia and cerebellar loops are known to participate differently in self-initiated (SI) and externally triggered (ET) movements. However, no previous neuroimaging studies have illustrated functional organization of these loops in vivo. Here, we aimed to functionally visualize these loops during motor execution using functional magnetic resonance imaging (fMRI) with structural equation modeling (SEM). Twelve normal subjects (24-29 years old) were scanned while performing five different frequencies of sequential left finger movements using either SI or ET movements. Random effect analysis combined with a parametric approach revealed a significant positive linear dependence of cerebral activation upon movement rate in the right Put, GPi, VL, SMC and SMA during SI tasks. During ET tasks, significant positive linear relationships were found in the right SMC, VPL, left CB and DN, whereas tendency for linear relationships was seen in the right PMv. SEM further showed significant interactions within the right basal ganglia-thalamo-motor loop during SI tasks. In contrast, there were significant interactions within the entire right cerebral hemisphere-left cerebellar loop involving CB, DN, VPL, PMv and SMC during ET tasks. Therefore, our modeling approach enabled identification of different contributions of the motor loops of basal ganglia and cerebellum to SI and ET tasks during motor execution.
authors.affiliation: Department of Neurology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Fukuoka 812-8582, Fukuoka, Japan. t_taniwa@neuro.med.kyushu-u.ac.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Taniwaki
authors.forename: Akira
authors.initials: A
authors.lastname: Okayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiura
authors.forename: Osamu
authors.initials: O
authors.lastname: Togao
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Takao
authors.initials: T
authors.lastname: Yamasaki
authors.forename: Katsuya
authors.initials: K
authors.lastname: Ogata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shigeto
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Ohyagi
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Kira
authors.forename: Shozo
authors.initials: S
authors.lastname: Tobimatsu
mesh_terms: D000328:Adult; D001479:Basal Ganglia / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D002531:Cerebellum / Q000033:anatomy & histology* / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008959:Models, Neurological; D009043:Motor Activity / Q000502:physiology*; D009068:Movement / Q000502:physiology