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Neuromagnetic Study on Higher Brain Functions

高级脑功能的神经磁学研究

基本信息

批准号：
04807008
负责人：
NAMBU Atsushi
金额：
$ 1.02万
依托单位：
Okazaki National Research Institute
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

A non-invasive technique, magnetoencephalography(MEG)measures the magnetic fields originating mainly from the intracellular current flow through the apical dendrites of cortical pyramidal neurons, which is caused by excitatory synaptic inputs. In this project, somatosensory-evoked, visually-evoked and movement-related magnetic fields were analyzed.(1)Cerebral magnetic fields elicited by the electrical stimulation of the median nerve were recorded. Responses at a peak latecy of 20 ms and 60 ms were generated in the primary somatosensory cortex(SI)over the contralateral scalp. The first component implies the existence of the intracellular current flow through the apical dendrites of pyramidal neurons directed from the deep layr to the superficial layr of SI, which seems to be caused by thalamic inputs to the deep layrs of SI.The second component seems to represent the synaptic activity at the superficial layr of SI probably through the intracortical neuronal circuits.(2)Visual stimuli we … More re presented at 4 or 8 positions around the center of the visual field. Waveform and distribution of the responses greatly varied depending on the stimulus position within the visual field. The electrical current dipole responsible for the first component(peak latency, 75 ms)was estimated to be around the midline of the occipital lobe, presumably the striate cortex.(3)Cerebral magnetic fields associated with visually initiated finger movements were studied. Magnetic field change preceding the onset of the movements was recorded over the contralateral scalp of the operating finger. The estimated current dipole of this component was directed anteriorly around the central sulcus. This implies the existence of the intradendritic current flow directed from the superficial layr to the deep layr of the anterior bank of the central sulcus. Previous animal experiments provide the interpretation of this component to be the activation of the hand area of the motor cortex through the cerebello-thalamo-cortical pathway.These results indicate that neuromagnetic recordings provide an effective non-invasive approach to the studies of the sensory, motor and integrative functions of the human brain, especially when combined with appropriate animal experiments. Less

脑磁图(MEG)是一种非侵入性技术，它测量的磁场主要来自兴奋性突触输入引起的流经皮质锥体神经元顶树突的细胞内电流。在本项目中，我们分析了体感、视觉和运动相关的磁场。(1)记录了电刺激正中神经所产生的脑磁场。在对侧头皮的初级躯体感觉皮层(SI)产生潜伏期为20ms和60ms的反应。第一个分量暗示细胞内电流流经锥体神经元顶端树突，从SI的深层流向浅层，这似乎是由丘脑对SI深层的输入引起的。第二个分量似乎代表SI浅层的突触活动，可能是通过皮质内神经元回路。(2)视觉刺激WE…更多的出现在视野中心周围的4或8个位置。根据刺激在视野中的位置不同，反应的波形和分布也有很大的不同。第一个成分(峰潜伏期，75ms)的电流偶极子估计在枕叶中线附近，可能是纹状皮质。(3)研究了与视觉启动手指运动相关的大脑磁场。运动开始前的磁场变化被记录在操作手指的对侧头皮上。估计该分量的电流偶极子指向中央沟的前方。这意味着存在从中央沟前岸浅层到深层的树突内流。以前的动物实验将这一成分解释为通过小脑-丘脑-皮质通路激活运动皮质的手部区域。这些结果表明，神经磁学记录为研究人脑的感觉、运动和综合功能提供了一种有效的非侵入性方法，特别是当结合适当的动物实验时。较少