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Study of activated area in the brain as sources of MEG and fMRI

研究大脑激活区域作为 MEG 和 fMRI 的来源

基本信息

批准号：
16300148
负责人：
IRAMINA Keiji
金额：
$ 9.47万
依托单位：
KYUSHU UNIVERSITY (2005)The University of Tokyo (2004)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16300148/
关键词：
MEG fMRI electrical sources in the brain maicro-SQUID high resolutional biomagnetic measurement 脳神経磁気刺激

项目摘要

This research aims at development of functional imaging of the brain which has the feature of the high spatial resolution and the high temporal resolution. The aim of this study is clarifying the relevance of nerve activity and a hemodynamics of the brain, and the relevance of the excitability of the electric activity within a brain, and the MEG and EEG. Moreover, the result obtained by magnetoencephalography and fMRI was compared and investigating change of a spatial and temporal signal and both relevance also inquired as a purpose. For an animal experiment, a high spatial resolution SQUID system was developed. This SQUID system enabled to measure and discriminate the magnetic field pattern under 800 μm resolution. It is possible to measure the magnetic activity at a tissue level with cellular-scale spatial resolution. Using this SQUID system, magnetic Fields produced by the compound nerve action current of the frog's sciatic nerve could be measured. Moreover, measurement of auditory … More evoked magnetic fields of mice within the 2 mm resolution was succeeded. However, it is difficult to estimate the source of MEG, because of the insufficiency of measurement points and low sensitivity. On the other hand, to clarify the relationships between neuronal activity and the hemodynamic response, activations of the primary somatosensory cortex were studied using MEG (magnetoencepahlogram) and fMRI (functional magnetic resonance imaging). Effects of the stimulus intensity of the electrical stimulation to the right thumb were investigated. When the stimulus intensity increased to the pain feeling in the fMRI experiments, a number of activated pixels and signal power which was defined as the integration value of NMR signal were increase steeply, however, this inclination did not correspond to neuronal activity. An increase of blood flow at the SI area continued for a longer duration and spread widely when the subject experienced pain exposed to strong stimulation. Neuronal activity at the SI area caused within 100 ms and did not spread widely even if the subject experienced pain. We also studied the short-term episodic memory using MEG and EEG. Sourece estimation showed a significant activation in the left inferior medial temporal lobe related to intentional encoding prosesses. Less

本研究旨在发展具有高空间分辨率和高时间分辨率的脑功能成像技术。本研究的目的是阐明神经活动和脑的血液动力学的相关性，以及脑内电活动的兴奋性与MEG和EEG的相关性。此外，将脑磁图和fMRI所获得的结果进行比较，并调查空间和时间信号的变化以及两者的相关性也作为目的。为了进行动物实验，研制了一套高空间分辨率的SQUID系统。该SQUID系统能够在800 μm分辨率下测量和鉴别磁场模式。它是可能的，以细胞尺度的空间分辨率在组织水平上测量的磁活动。利用该SQUID系统，可以测量青蛙坐骨神经复合神经动作电流产生的磁场。此外，听觉测量 ...更多信息在2mm分辨率内成功地诱发了小鼠的磁场。然而，由于测量点的不足和灵敏度低，很难估计MEG的来源。另一方面，为了阐明神经元活动与血流动力学反应之间的关系，使用MEG（磁脑图）和fMRI（功能磁共振成像）研究了初级躯体感觉皮层的激活。研究了电刺激强度对右拇指的影响。在fMRI实验中，当刺激强度增加到痛觉时，激活像素数和信号功率（定义为核磁共振信号的积分值）急剧增加，但这种趋势与神经元的活动并不对应。当受试者经历暴露于强刺激的疼痛时，SI区域的血流量增加持续较长时间并广泛传播。SI区域的神经元活动在100 ms内引起，即使受试者经历疼痛也不会广泛传播。我们还用脑磁图（MEG）和脑电图（EEG）研究了短时情景记忆。源性估计显示左侧内侧下颞叶与有意编码过程相关的显著激活。少