Age-related alterations of the functional interactions within the basal ganglia and cerebellar motor loops in vivo.
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.
Taniwaki
Takayuki
T
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
Okayama
Akira
A
Yoshiura
Takashi
T
Togao
Osamu
O
Nakamura
Yasuhiko
Y
Yamasaki
Takao
T
Ogata
Katsuya
K
Shigeto
Hiroshi
H
Ohyagi
Yasumasa
Y
Kira
Jun-Ichi
J
Tobimatsu
Shozo
S
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