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

一种非侵入性技术，磁脑摄影（MEG）测量的磁场主要源于细胞内流穿过皮质金字塔神经元的顶端树突，这是由兴奋性突触输入引起的。在该项目中，分析了体感诱发的，视觉诱发的磁场和与运动相关的磁场。（1）记录了中位神经的电刺激引起的大脑磁场。在对比度头皮上，在初级体感皮层（SI）中产生了20毫秒和60 ms的峰值的响应。第一个组成部分意味着在从深层到si表面的锥体神经元的顶端树突中的存在，这似乎是由丘脑输入引起的，这是由Si的深层产生的。 …在视野中心附近有4或8个位置出现。波形和响应的分布巨大，取决于视野内的刺激位置。负责第一组件的电流偶极子（峰潜伏期为75 ms）估计在枕叶的中线附近，大概是策略皮层。（3）与视觉启动的手指运动相关的脑磁场是研究的。在手指的对比度头皮上记录了运动开始之前的磁场变化。该组件的估计电流偶极子在中央沟周围向前定向。这意味着从表层底部到中央沟的前库深层的内端电流流的存在。先前的动物实验提供了对该成分的解释，即通过小脑 - thalamo-cortical途径的运动皮层的手动区域的激活。这些结果表明，神经磁记录为人类大脑的感觉，运动和综合功能的研究提供了一种有效的非侵入性方法，尤其是与适当的动物实验结合在一起时。较少的