Study of motor programming in humans using magnetoencephalography, magnetic stimulation and fMRI.

a .人的眼动控制：磁刺激对反应时间影响的研究表明，声音或与磁刺激相关的感觉刺激引起的感觉间促进对反应时间有显著影响。这表明在磁刺激反应时间实验中，我们必须注意感觉间促进。我们发现，在fMRI研究中，用8字形线圈对颅骨进行磁刺激所确定的运动点位于激活区域上方，这意味着8字形线圈激活的皮质区域正好位于8字形线圈的中心下方。基于这些发现，我们研究了8字形线圈磁刺激对眼球运动的皮层控制。顶叶后皮层主要在提示后8ms起重要作用，通常发生在提示后200ms左右。双脉冲刺激对人体运动皮层的抑制作用阈下条件反射刺激对mep的影响可能是由GABA介导的皮层内抑制机制产生的，该机制为我们提供了精细的运动。通过记录FDI肌肉，我们发现这种抑制作用主要发生在13波而不是11波。我们对各种神经系统疾病患者手部肌肉的研究表明，皮质肌阵挛、肌张力障碍、运动障碍和帕金森病患者的这种抑制减少或不存在，但在共济失调、舞蹈病或感觉障碍患者中不受干扰。这表明从基底神经节到运动皮层的输入一定对用这种方法研究的运动皮质内抑制系统有一定的影响，但从感觉皮层或小脑的输入一定很少或没有影响。我们也用同样的成对脉冲刺激方法研究了胸锁乳突肌。这表明颈部运动区存在与手部运动区相同的抑制系统，并且该系统与痉挛性斜颈患者有关，这是一种肌张力障碍。少

A.Oculomotor control in humansOur study on the effect of magnetic stimulation on the reaction time revealed that intersensory facilitation elicited by sound or sensory stimulus associated with magnetic stimulation has significant influence on the reaction times. This indicates that we have to mind the intersensory facilitation in the reaction time experiments using magnetic stimulation. We showed that the motor point determined by magnetic stimulation over the skull with a figure-8-shaped coil was positioned over the activated area in fMRI study, which implies that the activated cortical area by a figure-8-shaped coil is just under the center of a figure-8-shaped coil. Based on these findings, we studied cortical control of eye movement in the antisaccade task by magnetic stimulation with a figure-8-shaped coil. The posterioparietal cortex plays an important role mainly at 8Oms after the cue in the antisaccade which usually occurs at about 200ms after the cue, and the frontal eye field … More at lOOms.B.Intracortical inhibition of the human motor cortex studied by a paired-palse stimulationThe effect of a subthreshold conditioning stimulus on MEPs to a succeeding suprathreshold test stimulus was considered to be produced by the intracortical inhibitory mechanisms probably mediated by GABA, which provides us refined movements. We revealed that this suppressive effect occurs mainly on 13-waves but not 11-waves by recording FDI muscles. Our studies of hand muscles in various neurological disorders demonstrated that this suppression was reduced or absent in patients with cortical myoclonus, dystonia, dyskinesia and Parkinson's disease, but not disturbed in patients with ataxia, chorea or sensory disturbances. This suggests that inputs from basal ganglia to motor cortex must have some influence on the intra-motor-cortical suppression system studied with this method, but inputs from the sensory cortex or cerebellum must have little or no influence. We also studied the sternocleidomastoid muscle (SCM) with the same paired-pulse stimulation method. This showed that the same inhibitory system as that of hand motor area is present in the neck motor area, and that this system is involved in patients with spasmodic torticollis which is a kind of dystonia. Less