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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，主要测量由兴奋性突触输入引起的通过皮层锥体神经元顶端树突的细胞内电流产生的磁场。在这个项目中，体感诱发，视觉诱发和运动相关的磁场进行了分析。（1）记录电刺激正中神经引起的脑磁场。在对侧头皮上的初级体感皮层（SI）中产生了20 ms和60 ms的峰值潜伏期的反应。第一个成分反映了从SI深层到浅层的锥体神经元顶树突的细胞内电流，这可能是由丘脑对SI深层的输入引起的，第二个成分可能反映了SI浅层的突触活动，可能是通过皮层内神经元回路。（2）视觉刺激， ...更多信息在视野中心周围的4或8个位置呈现。反应的波形和分布根据刺激在视野内的位置而变化很大。负责第一个组成部分（峰值潜伏期，75毫秒）的电流偶极子估计是围绕中线的枕叶，大概是纹状体皮质。（3）研究了视觉启动手指运动的脑磁场。磁场变化的发病前的运动记录在对侧头皮的操作手指。估计电流偶极子的这一组成部分是指向前方周围的中央沟。这表明树突内存在由中央沟前堤浅层向深层的电流。以往的动物实验解释了这一成分是通过小脑-丘脑-皮层通路激活运动皮层的手区，这些结果表明，神经磁记录提供了一个有效的非侵入性的方法来研究人类大脑的感觉，运动和综合功能，特别是当与适当的动物实验相结合。少