Motor cortex activation is related to force of squeezing
Motor cortex activation is related to force of squeezing
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DOI：
10.1002/hbm.10040
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发表时间：
2002-08-01
影响因子：
4.8
通讯作者：
Rosen, BR
中科院分区：
文献类型：
--
作者：
Cramer, SC;Weisskoff, RM;Rosen, BR
灵长类动物研究表明，运动皮层神经元的活动随着运动力量的增加而增加。在人类中，这种关系在握力（例如挤压）期间很少受到研究，并且之前仅在狭窄的力范围内进行了评估。对八名健康受试者进行了功能性核磁共振检查，这些受试者在休息和右手挤压之间交替使用三种力量水平之一。在扫描过程中，使用测力计记录运动表现。在每个力水平下，测量左感觉运动皮层、右感觉运动皮层和中线辅助运动区的激活量。在左侧感觉运动皮层中，还评估了信号变化百分比。三个力水平产生的力范围从 4.9 N 到 276 N 不等。在左侧感觉运动皮层中，随着力的增大，激活量显着增加。信号变化百分比也随着力的增大而增加，并且与激活量密切相关。在辅助运动区，激活量随着力量的增加而显着增加，但受试者之间的差异更大。在右侧感觉运动皮层中，更大力量的更大激活量的趋势并未达到显着性。偏侧性指数是对侧与同侧感觉运动皮层激活相对程度的表达，在三个力水平上没有变化。挤压力的增加与对侧感觉运动皮层和辅助运动区激活的增加有关。这种关系在人手能够产生的所有力量中都被发现。使用有效、可靠的方法来评估功能性 MRI 期间的运动行为对于临床应用可能很重要。 (C) 2002 Wiley-Liss, Inc.
Primate studies have demonstrated that motor cortex neurons show increased activity with increased force of movement. In humans, this relationship has received little study during a power grip such as squeezing, and has previously only been evaluated across a narrow range of forces. Functional MRI was performed in eight healthy subjects who alternated between rest and right hand squeezing at one of three force levels. During scanning, motor performances were recorded using a dynamometer. At each force level, activation volume was measured within left sensorimotor cortex, right sensorimotor cortex, and a midline supplementary motor area. In left sensorimotor cortex, % signal change was also assessed. The range of force generated across the three force levels varied from 4.9 N to 276 N. In left sensorimotor cortex, activation volume increased significantly with greater force. The % signal change also increased with greater force and correlated closely with activation volume. In supplementary motor area, activation volume increased significantly with increasing force, but with greater intersubject variability. In right sensorimotor cortex, a trend for larger activation volumes with greater force did not reach significance. The laterality index, an expression of the relative degree of contralateral vs. ipsilateral sensorimotor cortex activation, did not change across the three force levels. Increased force of squeezing is associated with increased contralateral sensorimotor cortex and supplementary motor area activation. This relationship was found across the full spectrum of forces that the human hand is capable of generating. Use of a valid, reliable method for assessing motor behavior during functional MRI may be important to clinical applications. (C) 2002 Wiley-Liss, Inc.