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，可测量主要源自流经皮层锥体神经元顶端树突的细胞内电流的磁场，该电流是由兴奋性突触输入引起的。分析与运动相关的磁场。(1)记录正中神经电刺激引起的脑磁场的峰值潜伏期的反应。 20 ms 和 60 ms 在对侧头皮上的初级体感皮层 (SI) 中产生。第一个分量意味着存在从 SI 深层流向浅层的锥体神经元顶端树突的细胞内电流。这似乎是由丘脑对 SI 深层的输入引起的。第二个组成部分似乎代表了 SI 浅层的突触活动，可能通过皮质内(2)视觉刺激在视野中心周围的 4 或 8 个位置呈现，响应的波形和分布根据视野内的刺激位置而变化很大。第一个组成部分（峰值潜伏期，75 毫秒）估计位于枕叶中线周围，可能是纹状皮层。(3) 研究了与视觉引发的手指运动相关的大脑磁场。运动的开始是在操作手指的对侧头皮上记录的，该部件的估计电流偶极子指向中央沟周围，这意味着存在从浅层指向深层的树突内电流。先前的动物实验将该成分解释为通过小脑-丘脑-皮质通路激活手部运动皮层区域。这些结果表明神经磁记录提供了有效的非侵入性方法来研究人脑的感觉、运动和综合功能，特别是与适当的动物实验相结合时。