Ouchi Y, Okada H, Yoshikawa E, Nobezawa S, Futatsubashi M
Positron Medical Center, Hamamatsu Medical Center, Hamakita, Japan.
Brain. 1999 Feb;122 ( Pt 2):329-38. doi: 10.1093/brain/122.2.329.
The regulatory mechanism of bipedal standing in humans remains to be elucidated. We investigated neural substrates for maintaining standing postures in humans using PET with our mobile gantry PET system. Normal volunteers were instructed to adopt several postures: supine with eyes open toward a target; standing with feet together and eyes open or eyes closed; and standing on one foot or with two feet in a tandem relationship with eyes open toward the target. Compared with the supine posture, standing with feet together activated the cerebellar anterior lobe and the right visual cortex (Brodmann area 18/19), and standing on one foot increased cerebral blood flow in the cerebellar anterior vermis and the posterior lobe lateral cortex ipsilateral to the weight-bearing side. Standing in tandem was accompanied by activation within the visual association cortex, the anterior and posterior vermis as well as within the midbrain. Standing with eyes closed activated the prefrontal cortex (Brodmann area 8/9). Our findings confirmed that the cerebellar vermis efferent system plays an important role in maintenance of standing posture and suggested that the visual association cortex may subserve regulating postural equilibrium while standing.
人类双足站立的调节机制仍有待阐明。我们使用移动龙门式正电子发射断层扫描（PET）系统，研究了人类维持站立姿势的神经基质。正常志愿者被要求采取几种姿势：仰卧睁眼看向目标；双脚并拢站立，睁眼或闭眼；单脚站立或双脚前后排列站立，睁眼看向目标。与仰卧姿势相比，双脚并拢站立激活了小脑前叶和右侧视觉皮层（布罗德曼18/19区），单脚站立增加了小脑前蚓部和负重侧同侧小脑后叶外侧皮层的脑血流量。前后排列站立伴随着视觉联合皮层、前后蚓部以及中脑的激活。闭眼站立激活了前额叶皮层（布罗德曼8/9区）。我们的研究结果证实，小脑蚓部传出系统在维持站立姿势中起重要作用，并表明视觉联合皮层可能有助于调节站立时的姿势平衡。
