Analysis and Measurement of Neuromagnetic Fields Elicited by Stimulations of Sensory Nerves

感觉神经刺激引起的神经磁场的分析和测量

基本信息

批准号：
61550287
负责人：
KURIKI Shinya
金额：
$ 0.83万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

We have studied the neuromagnetic fields which are evoked by peripheral nerve and auditory stimulations. The measurement system we have developed consists of a mapping apparatus which includes a 2nd-order gradiometer and SQUID, a somatosensory and auditory stimulator, and a signal processor for averaging and amplitude and phase detection.In the somatosensory evoked fields (SEF), responses have two main peaks at 80 and 160 ms after the stimulus, while responses of the auditory evoked fields (AEF) have main peaks at 100 and 180 ms latencies. Estimation of parameters of a current-dipole source based on a least-squares fit to the mapping measured data has indicated that the dipole is located at somatosensory and auditory cortexes for the SEF and AEF, respectively. These locations agree well with MRI observation. The dipole moments are 5-30 nAm.In the steady state SEF responses to repeated stimuli, phase lag exhibits a linear dependence on the frequency of the stimuli. The linear relation gives three values of the time lag, two of which agree with the latencies of the main peaks in the transient response. The shortest time lag is attributed to the latency of the early component.In the AEFs with tone burst and short verbal sounds like/a/and/ka/, responses to the verbal sounds have similar peaks to the tone burst response. Estimated moments of the current-dipole sources for the tones and verbal sounds are nearly the same or larger in the right hemisphere than in the left hemisphere. There seems a slight difference in the location of the dipoles of the tones and verbal sounds in the left hemisphere.

我们已经研究了神经磁场，这些神经磁场被周围神经和听觉刺激引起。我们开发的测量系统由映射设备组成，其中包括2阶梯度仪和鱿鱼，体感和听觉刺激器，以及用于平均，振幅和相位检测的信号处理器。刺激后80和160毫秒的两个主要峰，而听觉诱发的田地（AEF）的响应在100和180 ms的潜伏期处有主要峰。基于与映射测量数据的最小二乘拟合的电流 - 偶极源的参数估计表明，偶极子分别位于SEF和AEF的体感和听觉皮层。这些位置与MRI观察非常吻合。偶极矩为5-30 NAM。在稳态SEF对重复刺激的响应中，相位滞后表现出对刺激频率的线性依赖性。线性关系给出了时间滞后的三个值，其中两个值与瞬态响应中主要峰的潜伏期一致。最短的时间滞后归因于早期组件的延迟。右半球的估计音源源和言语声音几乎相同或更大。音调的偶极子的位置和左半球的言语声音的位置似乎略有差异。