Integrative mechanisms of excitation and inhibition of the motor cortex and supplementary

本研究对人和大鼠运动皮层和辅助感觉运动区的兴奋和抑制的整合机制进行了研究，主要结果如下：1.慢性硬膜下电极电刺激顽固性癫痫患者运动皮层和辅助感觉运动区的运动功能：人类运动皮层的兴奋和抑制机制参与诱发运动诱发电位（MEP）和沉默期（SP）。而负运动区和辅助感觉运动区与SP.2的诱发无关。反射性肌阵挛患者感觉和运动皮质之间的传导时间：通过两种方法估计感觉和运动皮质之间的传导时间（皮质延迟）。一种方法是磁刺激感觉皮层和运动皮层诱发两次MEP潜伏期的不同时间。另一组为C反射、SEP（N20）和ME的测定 ...更多信息 计算皮层延迟（皮层延迟C反射-N20-MEP）。从这些研究中可以明显看出，感觉皮层和运动皮层之间的传导时间约为4 msec，皮层反射肌阵挛患者和皮质基底节变性患者的C反射（长环反射）通路不同.从大鼠脑内电压门控钠通道活动分析脑功能：大鼠脑内电压门控钠通道活动在重复经颅磁刺激（rTMS，刺激次数：1,500次/天）后立即显著增加，连续7天（总刺激次数：10,500次）。在rTMS刺激后14 d，这些活动显著增加，刺激后28 d恢复到基线水平。rTMS后大鼠海马电压门控性钠通道的数目保持稳定，而电压门控性钠通道的活动则无明显增加，提示rTMS对大鼠海马电压门控性钠通道活动的影响是可逆的。难治性颞叶癫痫患者颞叶内侧电压门控性钠通道的数量明显减少，尽管这些活动在正常水平。这些结果表明，在这些患者的海马没有过度兴奋.经颅磁刺激运动皮层诱发的运动诱发电位（MEP）研究证实，人类不存在锥体交叉。在某些患者中，运动皮质无疑支配同侧上肢和下肢的肌肉。此外，体感诱发电位（SEP）研究证实，躯体感觉通路也上行至同侧感觉皮层（3b区），但不交叉。少

We studied the integrative mechanisms of excitation and inhibition of motor cortex and supplementary sensorimotor areas in human and rat in which the following results were obtained.1. Motor function by the electrical stimulation of chronic subdural electrodes covering the motor cortex and supplementary sensorimotor areas in the patients with intractable epilepsy :The excitation and inhibition mechanisms of the motor cortex in human participate in eliciting motor evoked potentials (MEP) and silent period (SP). However, the negative motor area and supplementary sensorimotor areas have no concern with elicitation of SP.2. Conduction time between sensory and motor cortices in the patients with reflex myoclonus :The conduction time (cortical delay) between sensory and motor cortices was estimated by two methods. The one method was different time between two MEP latencies elicited by magnetic stimulation of sensory and motor cortices. The other was measurements of C reflex, SEP (N20) and ME … More P latencies from which calculated the cortical delay (cortical delay C reflex - N20 - MEP). It becomes evident from these studies that the conduction time between sensory and motor cortices is approximately 4 msec, and the pathways of C reflex (long loop reflex) are different between the patients with cortical reflex myoclonus and those with corticobasal degeneration.3. Brain function analyzing from the activities of voltage-gated sodium channels in rat brain :The activities of voltage-gated sodium channels in the rat brain were significantly increased immediately after the repetitive transcranial magnetic stimulation (rTMS, number of stimuli : 1,500/day) for 7 days consecutively (total number of stimuli : 10,500). Furthermore, those activities were significantly increased at 14th day after the rTMS, and returned to the baseline levels at 28th day after the stimulation. The number of voltage-gated soduim channels were stable after the rTMS.On the other hand, the activities of voltage-gated sodium channels at the hippocampus in the rat were not significantly increased after the rTMS.These results suggest that the changes of these activities evoked by rTM are reversible in the rat brain. The number of voltage-gated sodium channels were decreased significantly at the mesial temporal lobe in the patients with intractable temporal lobe epilepsy, although these activities were in normal levels. These results suggest that there is no excessive excitation in the hippocampus in those patients.4. No pyramidal decussation in human has been proved by the study of MEP elicited by transcranial magnetic stimulation of the motor cortex. The motor cortex undoubtedly innervates ipsilateral muscles of the upper and lower extremities in some patients. Furthermore, somatosensory pathways also ascends to the ipsilateral sensory cortex (3b area) without decussation in those subjects which has been proved by SEP study. Less