Scholz V H, Flaherty A W, Kraft E, Keltner J R, Kwong K K, Chen Y I, Rosen B R, Jenkins B G
MGH-NMR Center, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02119, USA.
Brain Res. 2000 Oct 6;879(1-2):204-15. doi: 10.1016/s0006-8993(00)02749-9.
We investigated the basal ganglia, motor cortex area 4, and supplementary motor area (SMA) using functional magnetic resonance imaging (fMRI) and five motor tasks: switching between finger and toe movements, writing, finger tapping, pronation/supination, and saccadic eye movements. We found reliable activation in the caudate nucleus and putamen in single subjects without the need for inter-subject averaging. Percent signal changes in basal ganglia were smaller by a factor of three than those in SMA or motor cortex (1% vs. 2.5-3%). There was a definite foot-dorsal, hand-ventral basal ganglia somatotopy, similar to prior data from primates. Saccadic eye movements activated the caudate nucleus significantly more than the other tasks did. Unilateral movements produced bilateral activation in the striatum even when motor cortex activation was unilateral. Surprisingly, bilateral performance of the tasks led, on average, to consistently smaller basal ganglia activation than did unilateral performance (P<0.001), suggesting less inhibition of contralateral movements during bilateral tasks. Moreover, there was a striking dominance pattern in basal ganglia motor activation: the left basal ganglia were more active than the right for right handers, regardless of the hand used. This lateralization appears much stronger than that previously reported for motor cortex. Comparisons of inter-subject and intra-subject reproducibility indicated a much larger variability in basal ganglia and SMA compared to motor cortex, in spite of similar percent signal changes in the latter two structures.
我们使用功能磁共振成像（fMRI）以及五项运动任务，对基底神经节、运动皮层4区和辅助运动区（SMA）进行了研究：手指与脚趾运动之间的切换、书写、手指敲击、旋前/旋后以及眼球扫视运动。我们发现，在单个体受试者的尾状核和壳核中可检测到可靠的激活，无需进行受试者间平均。基底神经节的信号变化百分比比SMA或运动皮层小三倍（1% 对 2.5 - 3%）。存在明确的足部背侧、手部腹侧的基底神经节躯体定位，类似于先前来自灵长类动物的数据。眼球扫视运动比其他任务更显著地激活了尾状核。即使运动皮层激活是单侧的，单侧运动也会在纹状体中产生双侧激活。令人惊讶的是，任务的双侧执行平均而言导致基底神经节的激活始终比单侧执行时小（P<0.001），这表明在双侧任务中对侧运动的抑制较少。此外，基底神经节运动激活存在明显的优势模式：右利手者的左侧基底神经节比右侧更活跃，无论使用哪只手。这种偏侧化似乎比先前报道的运动皮层的偏侧化要强得多。受试者间和受试者内可重复性的比较表明，尽管基底神经节和SMA与运动皮层的信号变化百分比相似，但基底神经节和SMA的变异性比运动皮层大得多。
