title: Age-related alterations of the functional interactions within the basal ganglia and cerebellar motor loops in vivo.
abstract: Aging may alter the motor functions of the basal ganglia and cerebellum; however, no previous neuroimaging study has investigated the effect of aging on the functional connectivity of the motor loops involving these structures. Recently, using fMRI with a parametric approach and structural equation modeling (SEM), we demonstrated a significant functional interaction within the basal ganglia-thalamo-motor (BGTM) loop during self-initiated (SI) finger movement in young normal subjects, whereas cerebro-cerebellar (CC) loop was mainly involved during externally triggered (ET) movement. We applied this method to 12 normal aged subjects (53-72 years old) in order to study the effect of age on BGTM and CC loops. Compared with the functional connectivity seen in young subjects, SEM showed decreased connectivity in BGTM loops during SI task, decreased interaction in the CC loop during ET task, and increased connectivity within motor cortices and between hemispheres during both types of tasks. These results suggest an age-related decline of cortico-subcortical connectivity with increased interactions between motor cortices. Aging effects on SI and ET movements are probably caused by functional alterations within BGTM and CC loops.
authors.affiliation: Department of Neurology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Fukuoka 812-8582, Fukuoka, Japan. ttaniwa@med.kurume-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; D000368:Aged; D000375:Aging / Q000502:physiology*; D001479:Basal Ganglia / Q000502:physiology*; D001931:Brain Mapping; D002531:Cerebellum / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009043:Motor Activity / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology*; D013788:Thalamus / Q000502:physiology