Horenstein Craig, Lowe Mark J, Koenig Katherine A, Phillips Micheal D
Cleveland Clinic, Ohio, USA.
Hum Brain Mapp. 2009 Apr;30(4):1397-412. doi: 10.1002/hbm.20610.
Sixteen healthy right-handed subjects performed a complex finger-tapping task that broadly activates the motor and premotor regions, including primary motor (M1), ventral premotor (PMv), and dorsal premotor (PMd) cortex. This task was performed with the right hand only, left hand only and both hands simultaneously. Behavioral performance and the possibility of mirror movements were controlled through the use of MRI-compatible gloves to monitor finger movements. Using spatially normalized ROIs from the Human Motor Area Template (HMAT), comparisons were made of the spatial extent and location of activation in the left and right motor regions between all three tasks. During unilateral right and left hand tapping, ipsilateral precentral gyrus activation occurred in all subjects, mainly in the PMv and PMd. Ipsilateral M1 activation was less consistent and shifted anteriorly within M1, towards the border of M1 and premotor cortex. Regions of ipsilateral activation were also activated during contralateral and bilateral tasks. Overall, 83%/70%/58% of the ipsilaterally activated voxels in M1/PMd/PMv were also activated during contralateral and bilateral tapping. The mean percent signal change of spatially overlapping activated voxels was similar in PMv and PMd between all three tasks. However, the mean percent signal change of spatially overlapping M1 activation was significantly less during ipsilateral tapping compared with contra- or bilateral tapping. Results suggest that the ipsilateral fMRI activation in unilateral motor tasks may not be inhibitory in nature, but rather may reflect part of a bilateral network involved in the planning and/or execution of tapping in the ipsilateral hand.
16名健康的右利手受试者进行了一项复杂的手指敲击任务，该任务广泛激活运动和运动前区，包括初级运动皮层（M1）、腹侧运动前区（PMv）和背侧运动前区（PMd）。该任务分别用右手、左手以及双手同时进行。通过使用与MRI兼容的手套来监测手指运动，从而控制行为表现和镜像运动的可能性。利用来自人类运动区模板（HMAT）的空间归一化感兴趣区域（ROIs），对所有三项任务中左右运动区激活的空间范围和位置进行了比较。在单侧右手和左手敲击过程中，所有受试者的同侧中央前回均有激活，主要在PMv和PMd。同侧M1的激活不太一致，且在M1内向前移位，靠近M1与运动前皮层的边界。在对侧和双侧任务中，同侧激活区域也被激活。总体而言，在对侧和双侧敲击过程中，M1/PMd/PMv中同侧激活体素的83%/70%/58%也被激活。在所有三项任务中，PMv和PMd中空间重叠激活体素的平均信号变化百分比相似。然而，与对侧或双侧敲击相比，同侧敲击时空间重叠的M1激活的平均信号变化百分比显著更低。结果表明，单侧运动任务中同侧功能磁共振成像激活本质上可能不是抑制性的，而是可能反映了参与同侧手敲击计划和/或执行的双侧网络的一部分。
